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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 config_prefix(prefix):
 """contextmanager for multiple invocations of API with a common prefix supported API functions: (register / get / set )__option Warning: This is not thread - safe, and won't work properly if you import the API functions into your module using the "from x import y" construct. Example: import pandas._config.config as cf with cf.config_prefix("display.font"):
 cf.register_option("color", "red") cf.register_option("size", " 5 pt") cf.set_option(size, " 6 pt") cf.get_option(size) etc' will register options "display.font.color", "display.font.size", set the """


    # Note: reset_option relies on set_option, and on key directly
    # it does not fit in to this monkey-patching scheme

    global register_option, get_option, set_option, reset_option

    def wrap(func):
        def inner(key, *args, **kwds):
            pkey = '{prefix}.{key}'.format(prefix=prefix, key=key)
            return func(pkey, *args, **kwds)

        return inner

    _register_option = register_option
    _get_option = get_option
    _set_option = set_option
    set_option = wrap(set_option)
    get_option = wrap(get_option)
    register_option = wrap(register_option)
    yield None
    set_option = _set_option
    get_option = _get_option
    register_option = _register_option