code: def test_lcs(seq_a, seq_b, expected):
      assert lcs(seq_a, seq_b) == expected
  
imports: import pytest
  from ignite.metrics.nlp.utils import lcs, modified_precision, ngrams
label_desc: Use image node_id 2 for calling a global function with example usage: test_lcs(seq_a, seq_b, expected) without return types