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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 _co_moving2angle_source(self, x, y):
 """ special case of the co_moving2angle definition at the source redshift :param x: :param y: :return: """

        T_z = self._T_z_source
        theta_x = x / T_z
        theta_y = y / T_z
        return theta_x, theta_y