code: def test_unique_tags():
      """
      Test getting the unique tags from a tree
      """
      text = "((SBARQ (WHNP (WP Who)) (SQ (VP (VBZ sits) (PP (IN in) (NP (DT this) (NN seat))))) (. ?)))"
  
      trees = tree_reader.read_trees(text)
  
      tags = Tree.get_unique_tags(trees)
      expected = [".", "DT", "IN", "NN", "VBZ", "WP"]
      assert tags == expected
  
imports: import pytest
  from stanza.models.constituency.parse_tree import Tree
  from stanza.models.constituency import tree_reader
  from stanza.tests import *
label_desc: Use image node_id 5 for calling a global function with example usage: test_unique_tags() without return types