'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.'

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)
