code: def test(self):
      return self._test_n_grams_based(ChrFScorer, 0.9)
  
imports: from .None import VizSeqScorerTestCase
  from vizseq.scorers.chrf import ChrFScorer
label_desc: Use image node_id 1 for calling the ChrFScorerTestCase obj's underlying member method code with example usage: obj.test() and returns: self