def METHOD_NAME(self):
    idx2 = k2gamma.translation_map(2)
    idx3 = k2gamma.translation_map(3)
    idx4 = k2gamma.translation_map(4)
    ref = np.empty((2, 3, 4, 2, 3, 4), dtype=int)
    for ix in range(2):
        for iy in range(3):
            for iz in range(4):
                for jx in range(2):
                    for jy in range(3):
                        for jz in range(4):
                            ref[ix,iy,iz,jx,jy,jz] = idx2[ix,jx] * 12 + idx3[iy,jy] * 4 + idx4[iz,jz]
    result = k2gamma.double_translation_indices([2,3,4])
    self.assertEqual(abs(ref.reshape(24,24) - result).max(), 0)