code: def test_initial_state(model=None):
      if model is None:
          model = SimpleModel()
      states = build_initial_state(model)
      assert len(states) == 1
      state = states[0]
  
      assert state.sentence_length == 3
      assert state.num_opens == 0
      # each stack has a sentinel value at the end
      assert len(state.word_queue) == 5
      assert len(state.constituents) == 1
      assert len(state.transitions) == 1
      assert state.word_position == 0
  
imports: import pytest
  from stanza.models.constituency import parse_transitions
  from stanza.models.constituency.base_model import SimpleModel, UNARY_LIMIT
  from stanza.models.constituency.parse_transitions import TransitionScheme, Shift, CloseConstituent, OpenConstituent
  from stanza.tests import *
label_desc: Use image node_id 2 for calling a global function with example usage: test_initial_state(model) without return types