Make a new metric function that calls the supplied metrics

    :arg functions metrics: metric functions
    :rtype: function

def make_multi_metric(*metrics):
    """Make a new metric function that calls the supplied metrics

    :arg functions metrics: metric functions
    :rtype: function
    """
    def multi_metric(name, count, elapsed):
        """Calls multiple metrics (closure)"""
        for m in metrics:
            m(name, count, elapsed)
    return multi_metric