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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 step(self, t, x_im1, v_im1_2, dt):
 """ Step forward the positions and velocities by the given timestep. Parameters dt : numeric The timestep to move forward. """


        x_i = x_im1 + v_im1_2 * dt
        F_i = self.F(t, np.vstack((x_i, v_im1_2)), *self._func_args)
        a_i = F_i[self.ndim:]

        v_i = v_im1_2 + a_i * dt / 2
        v_ip1_2 = v_i + a_i * dt / 2

        return x_i, v_i, v_ip1_2