ortools.linear_solver.linear_solver_pb2

496  def init(self, **kwargs):
497    self._cached_byte_size = 0
498    self._cached_byte_size_dirty = len(kwargs) > 0
499    self._fields = {}
500    # Contains a mapping from oneof field descriptors to the descriptor
501    # of the currently set field in that oneof field.
502    self._oneofs = {}
503
504    # _unknown_fields is () when empty for efficiency, and will be turned into
505    # a list if fields are added.
506    self._unknown_fields = ()
507    # _unknown_field_set is None when empty for efficiency, and will be
508    # turned into UnknownFieldSet struct if fields are added.
509    self._unknown_field_set = None      # pylint: disable=protected-access
510    self._is_present_in_parent = False
511    self._listener = message_listener_mod.NullMessageListener()
512    self._listener_for_children = _Listener(self)
513    for field_name, field_value in kwargs.items():
514      field = _GetFieldByName(message_descriptor, field_name)
515      if field is None:
516        raise TypeError('%s() got an unexpected keyword argument "%s"' %
517                        (message_descriptor.name, field_name))
518      if field_value is None:
519        # field=None is the same as no field at all.
520        continue
521      if field.label == _FieldDescriptor.LABEL_REPEATED:
522        copy = field._default_constructor(self)
523        if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:  # Composite
524          if _IsMapField(field):
525            if _IsMessageMapField(field):
526              for key in field_value:
527                copy[key].MergeFrom(field_value[key])
528            else:
529              copy.update(field_value)
530          else:
531            for val in field_value:
532              if isinstance(val, dict):
533                copy.add(**val)
534              else:
535                copy.add().MergeFrom(val)
536        else:  # Scalar
537          if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
538            field_value = [_GetIntegerEnumValue(field.enum_type, val)
539                           for val in field_value]
540          copy.extend(field_value)
541        self._fields[field] = copy
542      elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
543        copy = field._default_constructor(self)
544        new_val = field_value
545        if isinstance(field_value, dict):
546          new_val = field.message_type._concrete_class(**field_value)
547        try:
548          copy.MergeFrom(new_val)
549        except TypeError:
550          _ReraiseTypeErrorWithFieldName(message_descriptor.name, field_name)
551        self._fields[field] = copy
552      else:
553        if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
554          field_value = _GetIntegerEnumValue(field.enum_type, field_value)
555        try:
556          setattr(self, field_name, field_value)
557        except TypeError:
558          _ReraiseTypeErrorWithFieldName(message_descriptor.name, field_name)

1312  def MergeFrom(self, msg):
1313    if not isinstance(msg, cls):
1314      raise TypeError(
1315          'Parameter to MergeFrom() must be instance of same class: '
1316          'expected %s got %s.' % (_FullyQualifiedClassName(cls),
1317                                   _FullyQualifiedClassName(msg.__class__)))
1318
1319    assert msg is not self
1320    self._Modified()
1321
1322    fields = self._fields
1323
1324    for field, value in msg._fields.items():
1325      if field.label == LABEL_REPEATED:
1326        field_value = fields.get(field)
1327        if field_value is None:
1328          # Construct a new object to represent this field.
1329          field_value = field._default_constructor(self)
1330          fields[field] = field_value
1331        field_value.MergeFrom(value)
1332      elif field.cpp_type == CPPTYPE_MESSAGE:
1333        if value._is_present_in_parent:
1334          field_value = fields.get(field)
1335          if field_value is None:
1336            # Construct a new object to represent this field.
1337            field_value = field._default_constructor(self)
1338            fields[field] = field_value
1339          field_value.MergeFrom(value)
1340      else:
1341        self._fields[field] = value
1342        if field.containing_oneof:
1343          self._UpdateOneofState(field)
1344
1345    if msg._unknown_fields:
1346      if not self._unknown_fields:
1347        self._unknown_fields = []
1348      self._unknown_fields.extend(msg._unknown_fields)
1349      # pylint: disable=protected-access
1350      if self._unknown_field_set is None:
1351        self._unknown_field_set = containers.UnknownFieldSet()
1352      self._unknown_field_set._extend(msg._unknown_field_set)

1375def _Clear(self):
1376  # Clear fields.
1377  self._fields = {}
1378  self._unknown_fields = ()
1379  # pylint: disable=protected-access
1380  if self._unknown_field_set is not None:
1381    self._unknown_field_set._clear()
1382    self._unknown_field_set = None
1383
1384  self._oneofs = {}
1385  self._Modified()

1452  def Modified(self):
1453    """Sets the _cached_byte_size_dirty bit to true,
1454    and propagates this to our listener iff this was a state change.
1455    """
1456
1457    # Note:  Some callers check _cached_byte_size_dirty before calling
1458    #   _Modified() as an extra optimization.  So, if this method is ever
1459    #   changed such that it does stuff even when _cached_byte_size_dirty is
1460    #   already true, the callers need to be updated.
1461    if not self._cached_byte_size_dirty:
1462      self._cached_byte_size_dirty = True
1463      self._listener_for_children.dirty = True
1464      self._is_present_in_parent = True
1465      self._listener.Modified()

1213  def IsInitialized(self, errors=None):
1214    """Checks if all required fields of a message are set.
1215
1216    Args:
1217      errors:  A list which, if provided, will be populated with the field
1218               paths of all missing required fields.
1219
1220    Returns:
1221      True iff the specified message has all required fields set.
1222    """
1223
1224    # Performance is critical so we avoid HasField() and ListFields().
1225
1226    for field in required_fields:
1227      if (field not in self._fields or
1228          (field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE and
1229           not self._fields[field]._is_present_in_parent)):
1230        if errors is not None:
1231          errors.extend(self.FindInitializationErrors())
1232        return False
1233
1234    for field, value in list(self._fields.items()):  # dict can change size!
1235      if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
1236        if field.label == _FieldDescriptor.LABEL_REPEATED:
1237          if (field.message_type._is_map_entry):
1238            continue
1239          for element in value:
1240            if not element.IsInitialized():
1241              if errors is not None:
1242                errors.extend(self.FindInitializationErrors())
1243              return False
1244        elif value._is_present_in_parent and not value.IsInitialized():
1245          if errors is not None:
1246            errors.extend(self.FindInitializationErrors())
1247          return False
1248
1249    return True

1119  def MergeFromString(self, serialized):
1120    serialized = memoryview(serialized)
1121    length = len(serialized)
1122    try:
1123      if self._InternalParse(serialized, 0, length) != length:
1124        # The only reason _InternalParse would return early is if it
1125        # encountered an end-group tag.
1126        raise message_mod.DecodeError('Unexpected end-group tag.')
1127    except (IndexError, TypeError):
1128      # Now ord(buf[p:p+1]) == ord('') gets TypeError.
1129      raise message_mod.DecodeError('Truncated message.')
1130    except struct.error as e:
1131      raise message_mod.DecodeError(e)
1132    return length   # Return this for legacy reasons.

1072  def SerializeToString(self, **kwargs):
1073    # Check if the message has all of its required fields set.
1074    if not self.IsInitialized():
1075      raise message_mod.EncodeError(
1076          'Message %s is missing required fields: %s' % (
1077          self.DESCRIPTOR.full_name, ','.join(self.FindInitializationErrors())))
1078    return self.SerializePartialToString(**kwargs)

1085  def SerializePartialToString(self, **kwargs):
1086    out = BytesIO()
1087    self._InternalSerialize(out.write, **kwargs)
1088    return out.getvalue()

814  def ListFields(self):
815    all_fields = [item for item in self._fields.items() if _IsPresent(item)]
816    all_fields.sort(key = lambda item: item[0].number)
817    return all_fields

838  def HasField(self, field_name):
839    try:
840      field = hassable_fields[field_name]
841    except KeyError as exc:
842      raise ValueError('Protocol message %s has no non-repeated field "%s" '
843                       'nor has presence is not available for this field.' % (
844                           message_descriptor.full_name, field_name)) from exc
845
846    if isinstance(field, descriptor_mod.OneofDescriptor):
847      try:
848        return HasField(self, self._oneofs[field].name)
849      except KeyError:
850        return False
851    else:
852      if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
853        value = self._fields.get(field)
854        return value is not None and value._is_present_in_parent
855      else:
856        return field in self._fields

863  def ClearField(self, field_name):
864    try:
865      field = message_descriptor.fields_by_name[field_name]
866    except KeyError:
867      try:
868        field = message_descriptor.oneofs_by_name[field_name]
869        if field in self._oneofs:
870          field = self._oneofs[field]
871        else:
872          return
873      except KeyError:
874        raise ValueError('Protocol message %s has no "%s" field.' %
875                         (message_descriptor.name, field_name))
876
877    if field in self._fields:
878      # To match the C++ implementation, we need to invalidate iterators
879      # for map fields when ClearField() happens.
880      if hasattr(self._fields[field], 'InvalidateIterators'):
881        self._fields[field].InvalidateIterators()
882
883      # Note:  If the field is a sub-message, its listener will still point
884      #   at us.  That's fine, because the worst than can happen is that it
885      #   will call _Modified() and invalidate our byte size.  Big deal.
886      del self._fields[field]
887
888      if self._oneofs.get(field.containing_oneof, None) is field:
889        del self._oneofs[field.containing_oneof]
890
891    # Always call _Modified() -- even if nothing was changed, this is
892    # a mutating method, and thus calling it should cause the field to become
893    # present in the parent message.
894    self._Modified()

1358  def WhichOneof(self, oneof_name):
1359    """Returns the name of the currently set field inside a oneof, or None."""
1360    try:
1361      field = message_descriptor.oneofs_by_name[oneof_name]
1362    except KeyError:
1363      raise ValueError(
1364          'Protocol message has no oneof "%s" field.' % oneof_name)
1365
1366    nested_field = self._oneofs.get(field, None)
1367    if nested_field is not None and self.HasField(nested_field.name):
1368      return nested_field.name
1369    else:
1370      return None

1388def _UnknownFields(self):
1389  warnings.warn(
1390      'message.UnknownFields() is deprecated. Please use the add one '
1391      'feature unknown_fields.UnknownFieldSet(message) in '
1392      'unknown_fields.py instead.'
1393  )
1394  if self._unknown_field_set is None:  # pylint: disable=protected-access
1395    # pylint: disable=protected-access
1396    self._unknown_field_set = containers.UnknownFieldSet()
1397  return self._unknown_field_set    # pylint: disable=protected-access

1400def _DiscardUnknownFields(self):
1401  self._unknown_fields = []
1402  self._unknown_field_set = None      # pylint: disable=protected-access
1403  for field, value in self.ListFields():
1404    if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
1405      if _IsMapField(field):
1406        if _IsMessageMapField(field):
1407          for key in value:
1408            value[key].DiscardUnknownFields()
1409      elif field.label == _FieldDescriptor.LABEL_REPEATED:
1410        for sub_message in value:
1411          sub_message.DiscardUnknownFields()
1412      else:
1413        value.DiscardUnknownFields()

1040  def ByteSize(self):
1041    if not self._cached_byte_size_dirty:
1042      return self._cached_byte_size
1043
1044    size = 0
1045    descriptor = self.DESCRIPTOR
1046    if descriptor._is_map_entry:
1047      # Fields of map entry should always be serialized.
1048      key_field = descriptor.fields_by_name['key']
1049      _MaybeAddEncoder(cls, key_field)
1050      size = key_field._sizer(self.key)
1051      value_field = descriptor.fields_by_name['value']
1052      _MaybeAddEncoder(cls, value_field)
1053      size += value_field._sizer(self.value)
1054    else:
1055      for field_descriptor, field_value in self.ListFields():
1056        _MaybeAddEncoder(cls, field_descriptor)
1057        size += field_descriptor._sizer(field_value)
1058      for tag_bytes, value_bytes in self._unknown_fields:
1059        size += len(tag_bytes) + len(value_bytes)
1060
1061    self._cached_byte_size = size
1062    self._cached_byte_size_dirty = False
1063    self._listener_for_children.dirty = False
1064    return size

792  def FromString(s):
793    message = cls()
794    message.MergeFromString(s)
795    return message

784  def RegisterExtension(field_descriptor):
785    field_descriptor.containing_type = cls.DESCRIPTOR
786    # TODO: Use cls.MESSAGE_FACTORY.pool when available.
787    # pylint: disable=protected-access
788    cls.DESCRIPTOR.file.pool._AddExtensionDescriptor(field_descriptor)
789    _AttachFieldHelpers(cls, field_descriptor)

685  def getter(self):
686    # TODO: This may be broken since there may not be
687    # default_value.  Combine with has_default_value somehow.
688    return self._fields.get(field, default_value)

685  def getter(self):
686    # TODO: This may be broken since there may not be
687    # default_value.  Combine with has_default_value somehow.
688    return self._fields.get(field, default_value)

685  def getter(self):
686    # TODO: This may be broken since there may not be
687    # default_value.  Combine with has_default_value somehow.
688    return self._fields.get(field, default_value)

685  def getter(self):
686    # TODO: This may be broken since there may not be
687    # default_value.  Combine with has_default_value somehow.
688    return self._fields.get(field, default_value)

685  def getter(self):
686    # TODO: This may be broken since there may not be
687    # default_value.  Combine with has_default_value somehow.
688    return self._fields.get(field, default_value)

685  def getter(self):
686    # TODO: This may be broken since there may not be
687    # default_value.  Combine with has_default_value somehow.
688    return self._fields.get(field, default_value)

1253  def FindInitializationErrors(self):
1254    """Finds required fields which are not initialized.
1255
1256    Returns:
1257      A list of strings.  Each string is a path to an uninitialized field from
1258      the top-level message, e.g. "foo.bar[5].baz".
1259    """
1260
1261    errors = []  # simplify things
1262
1263    for field in required_fields:
1264      if not self.HasField(field.name):
1265        errors.append(field.name)
1266
1267    for field, value in self.ListFields():
1268      if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
1269        if field.is_extension:
1270          name = '(%s)' % field.full_name
1271        else:
1272          name = field.name
1273
1274        if _IsMapField(field):
1275          if _IsMessageMapField(field):
1276            for key in value:
1277              element = value[key]
1278              prefix = '%s[%s].' % (name, key)
1279              sub_errors = element.FindInitializationErrors()
1280              errors += [prefix + error for error in sub_errors]
1281          else:
1282            # ScalarMaps can't have any initialization errors.
1283            pass
1284        elif field.label == _FieldDescriptor.LABEL_REPEATED:
1285          for i in range(len(value)):
1286            element = value[i]
1287            prefix = '%s[%d].' % (name, i)
1288            sub_errors = element.FindInitializationErrors()
1289            errors += [prefix + error for error in sub_errors]
1290        else:
1291          prefix = name + '.'
1292          sub_errors = value.FindInitializationErrors()
1293          errors += [prefix + error for error in sub_errors]
1294
1295    return errors

496  def init(self, **kwargs):
497    self._cached_byte_size = 0
498    self._cached_byte_size_dirty = len(kwargs) > 0
499    self._fields = {}
500    # Contains a mapping from oneof field descriptors to the descriptor
501    # of the currently set field in that oneof field.
502    self._oneofs = {}
503
504    # _unknown_fields is () when empty for efficiency, and will be turned into
505    # a list if fields are added.
506    self._unknown_fields = ()
507    # _unknown_field_set is None when empty for efficiency, and will be
508    # turned into UnknownFieldSet struct if fields are added.
509    self._unknown_field_set = None      # pylint: disable=protected-access
510    self._is_present_in_parent = False
511    self._listener = message_listener_mod.NullMessageListener()
512    self._listener_for_children = _Listener(self)
513    for field_name, field_value in kwargs.items():
514      field = _GetFieldByName(message_descriptor, field_name)
515      if field is None:
516        raise TypeError('%s() got an unexpected keyword argument "%s"' %
517                        (message_descriptor.name, field_name))
518      if field_value is None:
519        # field=None is the same as no field at all.
520        continue
521      if field.label == _FieldDescriptor.LABEL_REPEATED:
522        copy = field._default_constructor(self)
523        if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:  # Composite
524          if _IsMapField(field):
525            if _IsMessageMapField(field):
526              for key in field_value:
527                copy[key].MergeFrom(field_value[key])
528            else:
529              copy.update(field_value)
530          else:
531            for val in field_value:
532              if isinstance(val, dict):
533                copy.add(**val)
534              else:
535                copy.add().MergeFrom(val)
536        else:  # Scalar
537          if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
538            field_value = [_GetIntegerEnumValue(field.enum_type, val)
539                           for val in field_value]
540          copy.extend(field_value)
541        self._fields[field] = copy
542      elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
543        copy = field._default_constructor(self)
544        new_val = field_value
545        if isinstance(field_value, dict):
546          new_val = field.message_type._concrete_class(**field_value)
547        try:
548          copy.MergeFrom(new_val)
549        except TypeError:
550          _ReraiseTypeErrorWithFieldName(message_descriptor.name, field_name)
551        self._fields[field] = copy
552      else:
553        if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
554          field_value = _GetIntegerEnumValue(field.enum_type, field_value)
555        try:
556          setattr(self, field_name, field_value)
557        except TypeError:
558          _ReraiseTypeErrorWithFieldName(message_descriptor.name, field_name)

1312  def MergeFrom(self, msg):
1313    if not isinstance(msg, cls):
1314      raise TypeError(
1315          'Parameter to MergeFrom() must be instance of same class: '
1316          'expected %s got %s.' % (_FullyQualifiedClassName(cls),
1317                                   _FullyQualifiedClassName(msg.__class__)))
1318
1319    assert msg is not self
1320    self._Modified()
1321
1322    fields = self._fields
1323
1324    for field, value in msg._fields.items():
1325      if field.label == LABEL_REPEATED:
1326        field_value = fields.get(field)
1327        if field_value is None:
1328          # Construct a new object to represent this field.
1329          field_value = field._default_constructor(self)
1330          fields[field] = field_value
1331        field_value.MergeFrom(value)
1332      elif field.cpp_type == CPPTYPE_MESSAGE:
1333        if value._is_present_in_parent:
1334          field_value = fields.get(field)
1335          if field_value is None:
1336            # Construct a new object to represent this field.
1337            field_value = field._default_constructor(self)
1338            fields[field] = field_value
1339          field_value.MergeFrom(value)
1340      else:
1341        self._fields[field] = value
1342        if field.containing_oneof:
1343          self._UpdateOneofState(field)
1344
1345    if msg._unknown_fields:
1346      if not self._unknown_fields:
1347        self._unknown_fields = []
1348      self._unknown_fields.extend(msg._unknown_fields)
1349      # pylint: disable=protected-access
1350      if self._unknown_field_set is None:
1351        self._unknown_field_set = containers.UnknownFieldSet()
1352      self._unknown_field_set._extend(msg._unknown_field_set)

1375def _Clear(self):
1376  # Clear fields.
1377  self._fields = {}
1378  self._unknown_fields = ()
1379  # pylint: disable=protected-access
1380  if self._unknown_field_set is not None:
1381    self._unknown_field_set._clear()
1382    self._unknown_field_set = None
1383
1384  self._oneofs = {}
1385  self._Modified()

1452  def Modified(self):
1453    """Sets the _cached_byte_size_dirty bit to true,
1454    and propagates this to our listener iff this was a state change.
1455    """
1456
1457    # Note:  Some callers check _cached_byte_size_dirty before calling
1458    #   _Modified() as an extra optimization.  So, if this method is ever
1459    #   changed such that it does stuff even when _cached_byte_size_dirty is
1460    #   already true, the callers need to be updated.
1461    if not self._cached_byte_size_dirty:
1462      self._cached_byte_size_dirty = True
1463      self._listener_for_children.dirty = True
1464      self._is_present_in_parent = True
1465      self._listener.Modified()

1213  def IsInitialized(self, errors=None):
1214    """Checks if all required fields of a message are set.
1215
1216    Args:
1217      errors:  A list which, if provided, will be populated with the field
1218               paths of all missing required fields.
1219
1220    Returns:
1221      True iff the specified message has all required fields set.
1222    """
1223
1224    # Performance is critical so we avoid HasField() and ListFields().
1225
1226    for field in required_fields:
1227      if (field not in self._fields or
1228          (field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE and
1229           not self._fields[field]._is_present_in_parent)):
1230        if errors is not None:
1231          errors.extend(self.FindInitializationErrors())
1232        return False
1233
1234    for field, value in list(self._fields.items()):  # dict can change size!
1235      if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
1236        if field.label == _FieldDescriptor.LABEL_REPEATED:
1237          if (field.message_type._is_map_entry):
1238            continue
1239          for element in value:
1240            if not element.IsInitialized():
1241              if errors is not None:
1242                errors.extend(self.FindInitializationErrors())
1243              return False
1244        elif value._is_present_in_parent and not value.IsInitialized():
1245          if errors is not None:
1246            errors.extend(self.FindInitializationErrors())
1247          return False
1248
1249    return True

1119  def MergeFromString(self, serialized):
1120    serialized = memoryview(serialized)
1121    length = len(serialized)
1122    try:
1123      if self._InternalParse(serialized, 0, length) != length:
1124        # The only reason _InternalParse would return early is if it
1125        # encountered an end-group tag.
1126        raise message_mod.DecodeError('Unexpected end-group tag.')
1127    except (IndexError, TypeError):
1128      # Now ord(buf[p:p+1]) == ord('') gets TypeError.
1129      raise message_mod.DecodeError('Truncated message.')
1130    except struct.error as e:
1131      raise message_mod.DecodeError(e)
1132    return length   # Return this for legacy reasons.

1072  def SerializeToString(self, **kwargs):
1073    # Check if the message has all of its required fields set.
1074    if not self.IsInitialized():
1075      raise message_mod.EncodeError(
1076          'Message %s is missing required fields: %s' % (
1077          self.DESCRIPTOR.full_name, ','.join(self.FindInitializationErrors())))
1078    return self.SerializePartialToString(**kwargs)

1085  def SerializePartialToString(self, **kwargs):
1086    out = BytesIO()
1087    self._InternalSerialize(out.write, **kwargs)
1088    return out.getvalue()

814  def ListFields(self):
815    all_fields = [item for item in self._fields.items() if _IsPresent(item)]
816    all_fields.sort(key = lambda item: item[0].number)
817    return all_fields

838  def HasField(self, field_name):
839    try:
840      field = hassable_fields[field_name]
841    except KeyError as exc:
842      raise ValueError('Protocol message %s has no non-repeated field "%s" '
843                       'nor has presence is not available for this field.' % (
844                           message_descriptor.full_name, field_name)) from exc
845
846    if isinstance(field, descriptor_mod.OneofDescriptor):
847      try:
848        return HasField(self, self._oneofs[field].name)
849      except KeyError:
850        return False
851    else:
852      if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
853        value = self._fields.get(field)
854        return value is not None and value._is_present_in_parent
855      else:
856        return field in self._fields

863  def ClearField(self, field_name):
864    try:
865      field = message_descriptor.fields_by_name[field_name]
866    except KeyError:
867      try:
868        field = message_descriptor.oneofs_by_name[field_name]
869        if field in self._oneofs:
870          field = self._oneofs[field]
871        else:
872          return
873      except KeyError:
874        raise ValueError('Protocol message %s has no "%s" field.' %
875                         (message_descriptor.name, field_name))
876
877    if field in self._fields:
878      # To match the C++ implementation, we need to invalidate iterators
879      # for map fields when ClearField() happens.
880      if hasattr(self._fields[field], 'InvalidateIterators'):
881        self._fields[field].InvalidateIterators()
882
883      # Note:  If the field is a sub-message, its listener will still point
884      #   at us.  That's fine, because the worst than can happen is that it
885      #   will call _Modified() and invalidate our byte size.  Big deal.
886      del self._fields[field]
887
888      if self._oneofs.get(field.containing_oneof, None) is field:
889        del self._oneofs[field.containing_oneof]
890
891    # Always call _Modified() -- even if nothing was changed, this is
892    # a mutating method, and thus calling it should cause the field to become
893    # present in the parent message.
894    self._Modified()