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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 _check_rot_sym(self, axis):
 """ Determines the rotational symmetry about supplied axis. Used only for symmetric top molecules which has possible rotational symmetry operations > 2. """

        min_set = self._get_smallest_set_not_on_axis(axis)
        max_sym = len(min_set)
        for i in range(max_sym, 0, -1):
            if max_sym % i != 0:
                continue
            op = SymmOp.from_axis_angle_and_translation(axis, 360 / i)
            rotvalid = self.is_valid_op(op)
            if rotvalid:
                self.symmops.append(op)
                self.rot_sym.append((axis, i))
                return i
        return 1