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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 hist_calls(fn):
 """ Decorator to check the distribution of return values of a function. """

    @functools.wraps(fn)
    def wrapper(*args, **kwargs):
        _histogram = histogram(
            "%s_calls" % pyformance.registry.get_qualname(fn))
        rtn = fn(*args, **kwargs)
        if type(rtn) in (int, float):
            _histogram.add(rtn)
        return rtn
    return wrapper