code: def test_get_valid_actions_uses_top_of_stack(self):
      state = GrammarState(
          ["s"], {}, {"s": [1, 2], "t": [3, 4]}, {}, is_nonterminal
      )
      assert state.get_valid_actions() == [1, 2]
      state = GrammarState(
          ["t"], {}, {"s": [1, 2], "t": [3, 4]}, {}, is_nonterminal
      )
      assert state.get_valid_actions() == [3, 4]
      state = GrammarState(
          ["e"],
          {},
          {"s": [1, 2], "t": [3, 4], "e": []},
          {},
          is_nonterminal,
      )
      assert state.get_valid_actions() == []
  
file_path: magnitude/pymagnitude/third_party/allennlp/tests/nn/decoding/grammar_state_test.py
imports: from __future__ import with_statement
  from __future__ import absolute_import
  import pytest
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.nn.decoding import GrammarState
label_desc: Use image node_id 2 for calling the TestGrammarState obj's underlying member method code with example usage: obj.test_get_valid_actions_uses_top_of_stack() without return types