def METHOD_NAME():
    from fealpy.pde.elliptic_1d import SinPDEData as PDE
    from fealpy.mesh import IntervalMesh
    from fealpy.functionspace import LagrangeFESpace as Space
    from fealpy.fem import DiffusionIntegrator
    from fealpy.fem import LinearForm
    from fealpy.fem import DirichletBC
    pde = PDE()
    domain = pde.domain()
    mesh = IntervalMesh.from_interval_domain(domain, nx=10)
    space = LagrangeFESpace(mesh, p=1)
    bform = BilinearForm(space)
    bform.add_domain_integrator(DiffusionIntegrator())
    bform.assembly()
    K = bform.get_matrix()