Redundant local variables in AllWindowedStream#reduce

public SingleOutputStreamOperator<T> reduce(ReduceFunction<T> function) {
    if (function instanceof RichFunction) {
        throw new UnsupportedOperationException(
                "ReduceFunction of reduce can not be a RichFunction. "
                        + "Please use reduce(ReduceFunction, WindowFunction) instead.");
    }

    // clean the closure
    function = input.getExecutionEnvironment().clean(function);

    String callLocation = Utils.getCallLocationName();
    String udfName = "AllWindowedStream." + callLocation;

    return reduce(function, new PassThroughAllWindowFunction<W, T>());
}