How to use the pyxem.generators.vdf_generator.VDFGenerator function in pyxem

def vdf_generator(diffraction_pattern, diffraction_vectors):
    return VDFGenerator(diffraction_pattern, diffraction_vectors)

def test_vdf_generator_from_map(diffraction_pattern):
    dvm = DiffractionVectors(np.array([[np.array([[1, 1],
                                                  [2, 2]]),
                                        np.array([[1, 1],
                                                  [2, 2],
                                                  [1, 2]])],
                                       [np.array([[1, 1],
                                                  [2, 2]]),
                                        np.array([[1, 1],
                                                  [2, 2]])]], dtype=object))
    dvm.axes_manager.set_signal_dimension(0)

    vdfgen = VDFGenerator(diffraction_pattern, dvm)
    assert isinstance(vdfgen, VDFGenerator)

def test_vdf_generator_init_with_vectors(self, diffraction_pattern):
        dvm = DiffractionVectors(np.array([[np.array([[1, 1],
                                                      [2, 2]]),
                                            np.array([[1, 1],
                                                      [2, 2],
                                                      [1, 2]])],
                                           [np.array([[1, 1],
                                                      [2, 2]]),
                                            np.array([[1, 1],
                                                      [2, 2]])]], dtype=object))
        dvm.axes_manager.set_signal_dimension(0)

        vdfgen = VDFGenerator(diffraction_pattern, dvm)
        assert isinstance(vdfgen.signal, ElectronDiffraction)
        assert isinstance(vdfgen.vectors, DiffractionVectors)

def test_vector_vdfs_without_vectors(self, diffraction_pattern):
        vdfgen = VDFGenerator(diffraction_pattern)
        vdfgen.get_vector_vdf_images(radius=2.)

def test_vdf_generator_init_without_vectors(self, diffraction_pattern):

        vdfgen = VDFGenerator(diffraction_pattern)
        assert isinstance(vdfgen.signal, ElectronDiffraction)
        assert isinstance(vdfgen.vectors, type(None))