code: def convert(cls, value, from_unit, to_unit):
          
          value_ms = value * cls.UNITS_IN_MILLISECONDS[from_unit]
          return value_ms / cls.UNITS_IN_MILLISECONDS[to_unit]
docs: Convert a value from one time unit to another.
  
          :return: the numeric value converted to the desired unit
          :rtype: float