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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 ITRF_position_velocity_error(self, t):
 """Return the ITRF position, velocity, and error at time `t`. The position is an x,y,z vector measured in au, the velocity is an x,y,z vector measured in au/day, and the error is a vector of possible error messages for the time or vector of times `t`. """

        rTEME, vTEME, error = self._position_and_velocity_TEME_km(t)
        rTEME /= AU_KM
        vTEME /= AU_KM
        vTEME *= DAY_S
        rITRF, vITRF = TEME_to_ITRF(t.ut1, rTEME, vTEME)
        return rITRF, vITRF, error