Chain function which returns a function.

    :param routine: routine to process.
    :return: routine embedding execution function.

def _process_function(chaining, routine):
    """Chain function which returns a function.

    :param routine: routine to process.
    :return: routine embedding execution function.
    """

    def processing(*args, **kwargs):
        """Execute routine with input args and kwargs and add reuslt in
        chaining.___.

        :param tuple args: routine varargs.
        :param dict kwargs: routine kwargs.
        :return: chaining chaining.
        :rtype: Chaining
        """

        result = routine(*args, **kwargs)
        chaining.___.append(result)

        return chaining

    return processing