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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 copy(self):
 """Return a copy of the equation"""

        return Eq(
            self._lhs, self._rhs, tag=self._tag,
            _prev_lhs=self._prev_lhs, _prev_rhs=self._prev_rhs,
            _prev_tags=self._prev_tags)