code: def test_double_metaphone(self):
      assert fn.doubleMetaphone("i") == {"A"}
      assert fn.doubleMetaphone("donald") == {"TNLT"}
      assert fn.doubleMetaphone("goofy") == {"KF"}
      assert fn.doubleMetaphone("cipciop") == {"SPSP", "SPXP"}
  
imports: import unittest
  from dedupe import predicate_functions
  from dedupe.cpredicates import ngrams
label_desc: Use image node_id 23 for calling the TestPredicateFunctions obj's underlying member method code with example usage: obj.test_double_metaphone() without return types