code: def test_top_down_compound_unary():
      text = "(ROOT (S (NP (DT The) (NNP Arizona) (NNPS Corporations) (NNP Commission)) (VP (VBD authorized) (NP (NP (DT an) (ADJP (CD 11.5)) (NN %) (NN rate) (NN increase)) (PP (IN at) (NP (NNP Tucson) (NNP Electric) (NNP Power) (NNP Co.))) (, ,) (UCP (ADJP (ADJP (RB substantially) (JJR lower)) (SBAR (IN than) (S (VP (VBN recommended) (NP (JJ last) (NN month)) (PP (IN by) (NP (DT a) (NN commission) (NN hearing) (NN officer))))))) (CC and) (NP (NP (QP (RB barely) (PDT half)) (DT the) (NN rise)) (VP (VBN sought) (PP (IN by) (NP (DT the) (NN utility)))))))) (. .)))"
  
      trees = tree_reader.read_trees(text)
      assert len(trees) == 1
  
      model = SimpleModel()
      transitions = transition_sequence.build_sequence(
          trees[0], transition_scheme=TransitionScheme.TOP_DOWN_COMPOUND
      )
  
      states = model.initial_state_from_gold_trees(trees)
      assert len(states) == 1
      state = states[0]
  
      for t in transitions:
          assert t.is_legal(state, model)
          state = t.apply(state, model)
  
      result = model.get_top_constituent(state.constituents)
      assert trees[0] == result
  
imports: import pytest
  from stanza.models.constituency import parse_transitions
  from stanza.models.constituency import transition_sequence
  from stanza.models.constituency import tree_reader
  from stanza.models.constituency.base_model import SimpleModel, UNARY_LIMIT
  from stanza.models.constituency.parse_transitions import *
  from stanza.tests import *
  from stanza.tests.constituency.test_parse_tree import CHINESE_LONG_LIST_TREE
label_desc: Use image node_id 10 for calling a global function with example usage: test_top_down_compound_unary() without return types