def METHOD_NAME():
    xi = GrassmannPoint(np.array([[-np.sqrt(2) / 2, -np.sqrt(2) / 4], [np.sqrt(2) / 2,
                                                                       -np.sqrt(2) / 4], [0, -np.sqrt(3) / 2]]))
    xj = GrassmannPoint(np.array([[0, np.sqrt(2) / 2], [1, 0], [0, -np.sqrt(2) / 2]]))
    xk = GrassmannPoint(np.array([[-0.69535592, -0.0546034], [-0.34016974, -0.85332868],
                                  [-0.63305978, 0.51850616]]))
    points = [xi, xj, xk]
    k = ProjectionKernel()
    k.calculate_kernel_matrix(points, points)
    kernel = np.matrix.round(k.kernel_matrix, 4)
    assert np.allclose(kernel, np.array([[2, 1.0063, 1.2345], [1.0063, 2, 1.0101], [1.2345, 1.0101, 2]]))