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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_ms(self):
 """ Get the elapsed time in milliseconds. returns floating point representation of elapsed time in seconds. """

        dt = datetime.datetime.now() - self.start_time
        return ((dt.days * 24 * 3600) + dt.seconds) * 1000  \
            + dt.microseconds / 1000.0