code: def run_forward_checks(model, num_states=1):
      """
      Run a couple small transitions and a forward pass on the given model
  
      Results are not checked in any way.  This function allows for
      testing that building models with various options results in a
      functional model.
      """
      states = test_parse_transitions.build_initial_state(
          model, num_states
      )
      model(states)
  
      shift = parse_transitions.Shift()
      shifts = [shift for _ in range(num_states)]
      states = parse_transitions.bulk_apply(model, states, shifts)
      model(states)
  
      open_transition = parse_transitions.OpenConstituent("NP")
      open_transitions = [open_transition for _ in range(num_states)]
      assert open_transition.is_legal(states[0], model)
      states = parse_transitions.bulk_apply(
          model, states, open_transitions
      )
      assert states[0].num_opens == 1
      model(states)
  
      states = parse_transitions.bulk_apply(model, states, shifts)
      model(states)
      states = parse_transitions.bulk_apply(model, states, shifts)
      model(states)
      assert states[0].num_opens == 1
      # now should have "mox", "opal" on the constituents
  
      close_transition = parse_transitions.CloseConstituent()
      close_transitions = [close_transition for _ in range(num_states)]
      assert close_transition.is_legal(states[0], model)
      states = parse_transitions.bulk_apply(
          model, states, close_transitions
      )
      assert states[0].num_opens == 0
  
      model(states)
  
imports: import os
  import pytest
  import torch
  from stanza.models.common import pretrain
  from stanza.models.common.utils import set_random_seed
  from stanza.models.constituency import parse_transitions
  from stanza.tests import *
  from stanza.tests.constituency import test_parse_transitions
  from stanza.tests.constituency.test_trainer import build_trainer
label_desc: Use image node_id 12 for calling a global function with example usage: run_forward_checks(model, num_states) without return types