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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 propagate(self, year, month=1, day=1, hour=0, minute=0, second=0.0):
 """Return a position and velocity vector for a given date and time."""


        j = jday(year, month, day, hour, minute, second)
        m = (j - self.jdsatepoch) * minutes_per_day
        r, v = sgp4(self, m)
        return r, v