code: def test_initial_state():
      """
      Test that the initial state has the expected shapes
      """
      ts = TransformerTreeStack(3, 5, 0.0)
      initial = ts.initial_state()
      assert len(initial) == 1
      assert initial.value.output.shape == torch.Size([5])
      assert initial.value.key_stack.shape == torch.Size([1, 5])
      assert initial.value.value_stack.shape == torch.Size([1, 5])
  
file_path: stanza/stanza/tests/constituency/test_transformer_tree_stack.py
imports: import pytest
  import torch
  from stanza.models.constituency.transformer_tree_stack import TransformerTreeStack
label_desc: Use image node_id 1 for calling a global function with example usage: test_initial_state() without return types