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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 flow_rate(vol_per_rev, rpm):
 """Return the flow rate from a pump given the volume of fluid pumped per revolution and the desired pump speed. :param vol_per_rev: Volume of fluid output per revolution (dependent on pump and tubing) :type vol_per_rev: float :param rpm: Desired pump speed in revolutions per minute :type rpm: float :return: Flow rate of the pump (mL/s) :rtype: float :Examples: <Quantity(0.25, 'milliliter / second')> """

    return (vol_per_rev * rpm).to(u.mL/u.s)