def _SetAllFieldTypes(self, package, desc_proto, scope):
    """Sets all the descriptor's fields's types.

    This method also sets the containing types on any extensions.

    Args:
      package: The current package of desc_proto.
      desc_proto: The message descriptor to update.
      scope: Enclosing scope of available types.
    """

    package = _PrefixWithDot(package)

    main_desc = self._GetTypeFromScope(package, desc_proto.name, scope)

    if package == '.':
      nested_package = _PrefixWithDot(desc_proto.name)
    else:
      nested_package = '.'.join([package, desc_proto.name])

    for field_proto, field_desc in zip(desc_proto.field, main_desc.fields):
      self._SetFieldType(field_proto, field_desc, nested_package, scope)

    for extension_proto, extension_desc in (
        zip(desc_proto.extension, main_desc.extensions)):
      extension_desc.containing_type = self._GetTypeFromScope(
          nested_package, extension_proto.extendee, scope)
      self._SetFieldType(extension_proto, extension_desc, nested_package, scope)

    for nested_type in desc_proto.nested_type:
      self._SetAllFieldTypes(nested_package, nested_type, scope)
Sets all the descriptor's fields's types.

    This method also sets the containing types on any extensions.

    Args:
      package: The current package of desc_proto.
      desc_proto: The message descriptor to update.
      scope: Enclosing scope of available types.
    
deps/protobuf/python/google/protobuf/descriptor_pool.py