def METHOD_NAME(self):
    """
    @brief 基函数为标量函数的标量空间, 以及基函数为向量函数的函数空间
    """
    space = self.space
    ldof = space.number_of_local_dofs()
    gdof = space.number_of_global_dofs()
    mesh = space.mesh
    NC = mesh.number_of_cells()
    CM = np.zeros((NC, ldof, ldof), dtype=space.ftype)
    for di in self.dintegrators:
        di.assembly_cell_matrix(space, out=CM)
    cell2dof = space.cell_to_dof()
    I = np.broadcast_to(cell2dof[:, :, None], shape=CM.shape)
    J = np.broadcast_to(cell2dof[:, None, :], shape=CM.shape)
    self._M = csr_matrix((CM.flat, (I.flat, J.flat)), shape=(gdof, gdof))