code: def encode_dict(values_dict):
      
      return {key: encode_value(value) for key, value in six.iteritems(values_dict)}
docs: Encode a dictionary into protobuf ``Value``-s.
  
      Args:
          values_dict (dict): The dictionary to encode as protobuf fields.
  
      Returns:
          Dict[str, ~google.cloud.firestore_v1beta1.types.Value]: A
          dictionary of string keys and ``Value`` protobufs as dictionary
          values.