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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 elapsed_time_from(start_time):
 """calculate time delta from latched time and current time"""

    time_then = make_time(start_time)
    time_now = datetime.utcnow().replace(microsecond=0)
    if time_then is None:
        return
    delta_t = time_now - time_then
    return delta_t