Return the correct validations dictionary for this parameter.
        First checks the method itself and then its class. If no validation is
        defined for this parameter, None is returned.

        :param method: A function to get the validation information from.
        :type method: Python function
        :param param: Name of the parameter to get validation information for.
        :type param: str

def _get_validation(self, method, param):
        """Return the correct validations dictionary for this parameter.
        First checks the method itself and then its class. If no validation is
        defined for this parameter, None is returned.

        :param method: A function to get the validation information from.
        :type method: Python function
        :param param: Name of the parameter to get validation information for.
        :type param: str
        """
        if hasattr(method, '_validations') and param in method._validations:
            return method._validations[param]
        elif (hasattr(method.im_class, '_validations') and
                param in method.im_class._validations):
            return method.im_class._validations[param]
        else:
            return None