USAGE:
>>>from speedometer import *
>>>speedometer = Speedometer(
>>>    MetricComposite(time=TimeMetric(), count=CountMetric())
>>>)
>>>speedometer.patch_object(obj, 'method')
>>>obj.method()
>>>stats = speedometer.pop_stats()
>>>print stats.count, stats.time
1 0.001

TIPS:
    For run tests on python < 2.7, you should install unittest2.
    And use nose.