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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def merge_response_func(func, key):
 """ Use this decorator to set a new merging response function to HTTP endpoints candidate function must have the following signature and be childs of BaseApi: ``` def merge_some_function(self, response, rison_args):
 ``` :param func: Name of the merge function where the key is allowed :param key: The key name for rison selection :return: None """


    def wrap(f):
        if not hasattr(f, "_response_key_func_mappings"):
            f._response_key_func_mappings = dict()
        f._response_key_func_mappings[key] = func
        return f

    return wrap