code: def test_unlabeled_tree():
      """
      Test the unlabeled error condition
      """
      text = "(ROOT ((Foo) (Bar)))"
      try:
          trees = tree_reader.read_trees(text)
          raise AssertionError("Expected an exception")
      except UnlabeledTreeError as e:
          assert e.line_num == 0
  
      trees = tree_reader.read_trees(text, broken_ok=True)
      assert len(trees) == 1
  
file_path: stanza/stanza/tests/constituency/test_tree_reader.py
imports: import pytest
  from stanza.models.constituency import tree_reader
  from stanza.models.constituency.tree_reader import MixedTreeError, UnclosedTreeError, UnlabeledTreeError
  from stanza.tests import *
label_desc: Use image node_id 8 for calling a global function with example usage: test_unlabeled_tree() without return types