code: def test_tversky_equivalence(seq1, seq2, alpha, beta, equiv):
      obs = tokens.tversky(seq1, seq2, alpha=alpha, beta=beta)
      obs_equiv = equiv(seq1, seq2)
      assert obs == obs_equiv
  
imports: import pytest
  from textacy.similarity import tokens
label_desc: Use image node_id 4 for calling a global function with example usage: test_tversky_equivalence(seq1, seq2, alpha, beta, equiv) without return types