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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 _normalize_http_methods(http_method):
 """ Normalizes Http Methods. Api Gateway allows a Http Methods of ANY. This is a special verb to denote all supported Http Methods on Api Gateway. :param str http_method: Http method :yield str: Either the input http_method or one of the _ANY_HTTP_METHODS (normalized Http Methods) """


        if http_method.upper() == 'ANY':
            for method in SamApiProvider._ANY_HTTP_METHODS:
                yield method.upper()
        else:
            yield http_method.upper()