Returns the type of the google.protobuf.Value message as an api.DataType.

  Returns None if the type of 'value' is not one of the types supported in
  api_pb2.DataType.

  Args:
    value: google.protobuf.Value message.

def _protobuf_value_type(value):
  """Returns the type of the google.protobuf.Value message as an api.DataType.

  Returns None if the type of 'value' is not one of the types supported in
  api_pb2.DataType.

  Args:
    value: google.protobuf.Value message.
  """
  if value.HasField("number_value"):
    return api_pb2.DATA_TYPE_FLOAT64
  if value.HasField("string_value"):
    return api_pb2.DATA_TYPE_STRING
  if value.HasField("bool_value"):
    return api_pb2.DATA_TYPE_BOOL
  return None