def METHOD_NAME(self):
    vs = self.vs
    vs_ref = vs.data[0, 0]
    D = get_DisplacementGradientMap(vs, vs_ref)
    assert D.axes_manager.navigation_shape == (2, 4)
    assert D.axes_manager.signal_shape == (3, 3)
    strain_map = D.get_strain_maps()