code: def test_token_aligner_project_single_token_index():
      source_tokens = ["abc", "def", "ghi", "jkl"]
      target_tokens = ["abc", "d", "ef", "ghi", "jkl"]
      ta = TokenAligner(source_tokens, target_tokens)
      m = ta.project_token_idxs(1)
      m_expected = np.array([1, 2])
      assert (m == m_expected).all()
  
imports: import numpy
  import pytest
  from jiant.utils.retokenize import TokenAligner, token_to_char
label_desc: Use image node_id 4 for calling a global function with example usage: test_token_aligner_project_single_token_index() without return types