How to use the libceed.EVAL_WEIGHT function in libceed

def test_402(ceed_resource, capsys):
  ceed = libceed.Ceed(ceed_resource)

  file_dir = os.path.dirname(os.path.abspath(__file__))
  qfs = load_qfs_so()

  qf_setup = ceed.QFunction(1, qfs.setup_mass,
                            os.path.join(file_dir, "test-qfunctions.h:setup_mass"))
  qf_setup.add_input("w", 1, libceed.EVAL_WEIGHT)
  qf_setup.add_input("dx", 1, libceed.EVAL_GRAD)
  qf_setup.add_output("qdata", 1, libceed.EVAL_NONE)

  qf_mass = ceed.QFunction(1, qfs.apply_mass,
                           os.path.join(file_dir, "t400-qfunction.h:apply_mass"))
  qf_mass.add_input("qdata", 1, libceed.EVAL_NONE)
  qf_mass.add_input("u", 1, libceed.EVAL_INTERP)
  qf_mass.add_output("v", 1, libceed.EVAL_INTERP)

  print(qf_setup)
  print(qf_mass)

  stdout, stderr = capsys.readouterr()
  with open(os.path.abspath("./output/test_402.out")) as output_file:
    true_output = output_file.read()

def test_400(ceed_resource):
  ceed = libceed.Ceed(ceed_resource)

  file_dir = os.path.dirname(os.path.abspath(__file__))
  qfs = load_qfs_so()

  qf_setup = ceed.QFunction(1, qfs.setup_mass,
                            os.path.join(file_dir, "test-qfunctions.h:setup_mass"))
  qf_setup.add_input("w", 1, libceed.EVAL_WEIGHT)
  qf_setup.add_input("dx", 1, libceed.EVAL_GRAD)
  qf_setup.add_output("qdata", 1, libceed.EVAL_NONE)

  qf_mass = ceed.QFunction(1, qfs.apply_mass,
                           os.path.join(file_dir, "test-qfunctions.h:apply_mass"))
  qf_mass.add_input("qdata", 1, libceed.EVAL_NONE)
  qf_mass.add_input("u", 1, libceed.EVAL_INTERP)
  qf_mass.add_output("v", 1, libceed.EVAL_INTERP)

  q = 8

  w_array = np.zeros(q, dtype="float64")
  u_array = np.zeros(q, dtype="float64")
  v_true  = np.zeros(q, dtype="float64")
  for i in range(q):
    x = 2.*i/(q-1) - 1

for j in range(p):
      indu[p*i+j] = i*(p-1) + j
  ru = ceed.ElemRestriction(nelem, p, nu, 2, indu, cmode=libceed.USE_POINTER)
  rui = ceed.IdentityElemRestriction(nelem, q, q*nelem, 1)

  # Bases
  bx = ceed.BasisTensorH1Lagrange(1, 1, 2, q, libceed.GAUSS)
  bu = ceed.BasisTensorH1Lagrange(1, 2, p, q, libceed.GAUSS)

  # QFunctions
  file_dir = os.path.dirname(os.path.abspath(__file__))
  qfs = load_qfs_so()

  qf_setup = ceed.QFunction(1, qfs.setup_mass,
                            os.path.join(file_dir, "test-qfunctions.h:setup_mass"))
  qf_setup.add_input("weights", 1, libceed.EVAL_WEIGHT)
  qf_setup.add_input("dx", 1, libceed.EVAL_GRAD)
  qf_setup.add_output("rho", 1, libceed.EVAL_NONE)

  qf_mass = ceed.QFunction(1, qfs.apply_mass_two,
                           os.path.join(file_dir, "test-qfunctions.h:apply_mass_two"))
  qf_mass.add_input("rho", 1, libceed.EVAL_NONE)
  qf_mass.add_input("u", 2, libceed.EVAL_INTERP)
  qf_mass.add_output("v", 2, libceed.EVAL_INTERP)

  # Operators
  op_setup = ceed.Operator(qf_setup)
  op_setup.set_field("weights", rxi, bx, libceed.VECTOR_NONE)
  op_setup.set_field("dx", rx, bx, libceed.VECTOR_ACTIVE)
  op_setup.set_field("rho", rui, libceed.BASIS_COLLOCATED,
                     libceed.VECTOR_ACTIVE)

for j in range(p):
      indu[p*i+j] = i*(p-1) + j
  ru = ceed.ElemRestriction(nelem, p, nu, 1, indu, cmode=libceed.USE_POINTER)
  rui = ceed.IdentityElemRestriction(nelem, q, q*nelem, 1)

  # Bases
  bx = ceed.BasisTensorH1Lagrange(1, 1, 2, q, libceed.GAUSS)
  bu = ceed.BasisTensorH1Lagrange(1, 1, p, q, libceed.GAUSS)

  # QFunctions
  file_dir = os.path.dirname(os.path.abspath(__file__))
  qfs = load_qfs_so()

  qf_setup = ceed.QFunction(1, qfs.setup_mass,
                            os.path.join(file_dir, "test-qfunctions.h:setup_mass"))
  qf_setup.add_input("weights", 1, libceed.EVAL_WEIGHT)
  qf_setup.add_input("dx", 1, libceed.EVAL_GRAD)
  qf_setup.add_output("rho", 1, libceed.EVAL_NONE)

  qf_mass = ceed.QFunction(1, qfs.apply_mass,
                           os.path.join(file_dir, "test-qfunctions.h:apply_mass"))
  qf_mass.add_input("rho", 1, libceed.EVAL_NONE)
  qf_mass.add_input("u", 1, libceed.EVAL_INTERP)
  qf_mass.add_output("v", 1, libceed.EVAL_INTERP)

  # Operators
  op_setup = ceed.Operator(qf_setup)
  op_setup.set_field("weights", rxi, bx, libceed.VECTOR_NONE)
  op_setup.set_field("dx", rx, bx, libceed.VECTOR_ACTIVE)
  op_setup.set_field("rho", rui, libceed.BASIS_COLLOCATED,
                     libceed.VECTOR_ACTIVE)