How to use the makefun._main_legacy_py.get_legacy_py_generator_body_template function in makefun

# create the body of the function to compile
    # The generated function body should dispatch its received arguments to the inner function.
    # For this we will pass as much as possible the arguments as keywords.
    # However if there are varpositional arguments we cannot
    assignments = [("%s=%s" % (k, k)) if is_kw else k for k, is_kw in params_to_kw_assignment_mode.items()]
    params_str = ', '.join(assignments)
    if inject_as_first_arg:
        params_str = "%s, %s" % (func_name, params_str)

    if _is_generator_func(func_impl):
        if sys.version_info >= (3, 3):
            body = "def %s\n    yield from _func_impl_(%s)\n" % (func_signature_str, params_str)
        else:
            from makefun._main_legacy_py import get_legacy_py_generator_body_template
            body = get_legacy_py_generator_body_template() % (func_signature_str, params_str)
    else:
        body = "def %s\n    return _func_impl_(%s)\n" % (func_signature_str, params_str)

    if iscoroutinefunction(func_impl):
        body = ("async " + body).replace('return', 'return await')

    # create the function by compiling code, mapping the `_func_impl_` symbol to `func_impl`
    protect_eval_dict(evaldict, func_name, params_names)
    evaldict['_func_impl_'] = func_impl
    f = _make(func_name, params_names, body, evaldict)

    # add the source annotation if needed
    if add_source:
        attrs['__source__'] = body

    # add the handler if needed