def METHOD_NAME(self):
    # 2D
    mps_shape = [8, 16, 16]
    mps = sim.birdcage_maps(mps_shape)
    ksp = sp.fft(mps, axes=[-1, -2])
    mps_rec, eig_val = app.EspiritCalib(
        ksp, output_eigenvalue=True, show_pbar=False
    ).run()
    np.testing.assert_allclose(eig_val, 1, rtol=0.01, atol=0.01)
    # 3D
    mps_shape = [8, 16, 16, 16]
    mps = sim.birdcage_maps(mps_shape)
    ksp = sp.fft(mps, axes=[-1, -2, -3])
    mps_rec, eig_val = app.EspiritCalib(
        ksp, output_eigenvalue=True, show_pbar=False
    ).run()
    np.testing.assert_allclose(eig_val, 1, rtol=0.01, atol=0.01)