<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def spin_py(self):
 """Returns the y-component of the spin of the primary mass."""

        return conversions.primary_spin(self.mass1, self.mass2, self.spin1y,
                                        self.spin2y)