code: def validate(self, value):
      
      if value is not None and not isinstance(value, self.data_type):
        raise datastore_errors.BadValueError(
            "Property %s must be convertible to a %s instance (%s)" %
            (self.name, self.data_type, value))
      return super(JsonProperty, self).validate(value)
docs: Validate value.
  
      Args:
        value: model value.
  
      Returns:
        Whether the specified value is valid data type value.
  
      Raises:
        BadValueError: when value is not of self.data_type type.