Takes serialized data and returns validation errors or None.

        :param data: Data to validate.
        :param context: Context data.
        :returns: validation errors or None

def validate(self, data, context=None):
        """Takes serialized data and returns validation errors or None.

        :param data: Data to validate.
        :param context: Context data.
        :returns: validation errors or None
        """
        try:
            self.load(data, context)
            return None
        except ValidationError as ve:
            return ve.messages