Adds the FileDescriptorProto and its types to this database.

    Args:
      file_desc_proto: The FileDescriptorProto to add.
    Raises:
      DescriptorDatabaseConflictingDefinitionError: if an attempt is made to
        add a proto with the same name but different definition than an
        exisiting proto in the database.

def Add(self, file_desc_proto):
    """Adds the FileDescriptorProto and its types to this database.

    Args:
      file_desc_proto: The FileDescriptorProto to add.
    Raises:
      DescriptorDatabaseConflictingDefinitionError: if an attempt is made to
        add a proto with the same name but different definition than an
        exisiting proto in the database.
    """
    proto_name = file_desc_proto.name
    if proto_name not in self._file_desc_protos_by_file:
      self._file_desc_protos_by_file[proto_name] = file_desc_proto
    elif self._file_desc_protos_by_file[proto_name] != file_desc_proto:
      raise DescriptorDatabaseConflictingDefinitionError(
          '%s already added, but with different descriptor.' % proto_name)

    # Add all the top-level descriptors to the index.
    package = file_desc_proto.package
    for message in file_desc_proto.message_type:
      self._file_desc_protos_by_symbol.update(
          (name, file_desc_proto) for name in _ExtractSymbols(message, package))
    for enum in file_desc_proto.enum_type:
      self._file_desc_protos_by_symbol[
          '.'.join((package, enum.name))] = file_desc_proto
    for extension in file_desc_proto.extension:
      self._file_desc_protos_by_symbol[
          '.'.join((package, extension.name))] = file_desc_proto
    for service in file_desc_proto.service:
      self._file_desc_protos_by_symbol[
          '.'.join((package, service.name))] = file_desc_proto