code: def test_token_to_char():
      expected_m = np.array(
          # T  h  i  s     i  s     a     t  e  s  t
          [
              [1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],  # This
              [0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0],  # is
              [0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0],  # a
              [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1],
          ],  # test
          dtype=np.int32,
      )
      m = token_to_char("This is a test")
      assert (m == expected_m).all()
  
imports: import numpy
  import pytest
  from jiant.utils.retokenize import TokenAligner, token_to_char
label_desc: Use image node_id 1 for calling a global function with example usage: test_token_to_char() without return types