<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def stderr_metric(name, count, elapsed):
 """A metric function that prints to standard error :arg str name: name of the metric :arg int count: number of items :arg float elapsed: time in seconds """

    _do_print(name, count, elapsed, file=sys.stderr)