def METHOD_NAME(symmetric_image):
    """Test that a symmetric image produces repeated sets of polar Fourier rays."""
    pf = symmetric_image
    # For C4 symmetry any two sets of rays seperated by 90 degrees should be equal.
    ntheta = pf.shape[0]  # ntheta is the number of rays in 180 degrees.
    assert np.allclose(abs(pf[: ntheta // 2]), abs(pf[ntheta // 2 :]), atol=1e-7)