def METHOD_NAME(self):
    flux1 = 1e-3 * np.array([1., 2., 3.])
    flux2 = 1e-3 * np.array([4., 5., 6.])
    # check with two shapes
    ek_species = self.make_default_ek_species()
    value_shape = tuple(ek_species.shape) + (3,)
    ek_species.add_boundary_from_shape(
        shape=self.wall_shape1, value=flux1,
        boundary_type=espressomd.electrokinetics.FluxBoundary)
    ek_species.add_boundary_from_shape(
        shape=self.wall_shape2, value=flux2 * np.ones(value_shape),
        boundary_type=espressomd.electrokinetics.FluxBoundary)
    self.check_boundary_flags(ek_species, "flux", flux1, flux2)
    # check with union of two shapes
    ek_species = self.make_default_ek_species()
    union = espressomd.shapes.Union()
    union.add([self.wall_shape1, self.wall_shape2])
    ek_species.add_boundary_from_shape(
        shape=union, value=flux1,
        boundary_type=espressomd.electrokinetics.FluxBoundary)
    self.check_boundary_flags(ek_species, "flux", flux1, flux1)