code: def test_one_gram_fingerprint(self):
      assert fn.oneGramFingerprint("don 456 ld") == {"456dlno"}
      assert fn.oneGramFingerprint("donald 1992") == {"129adlno"}
      assert fn.oneGramFingerprint(" g00fy  ") == {"0fgy"}
      assert fn.oneGramFingerprint(" c1p   c10p ") == {"01cp"}
  
      def prevImpl(field: str):
          return {
              "".join(
                  sorted(set(ngrams(field.replace(" ", ""), 1)))
              ).strip()
          }
  
      assert fn.oneGramFingerprint("don 456 ld"), prevImpl("don 456 ld")
      assert fn.oneGramFingerprint("donald 1992"), prevImpl(
          "donald 1992"
      )
      assert fn.oneGramFingerprint(" g00fy  "), prevImpl(" g00fy  ")
      assert fn.oneGramFingerprint(" c1p   c10p "), prevImpl(
          " c1p   c10p "
      )
  
imports: import unittest
  from dedupe import predicate_functions
  from dedupe.cpredicates import ngrams
label_desc: Use image node_id 14 for calling the TestPredicateFunctions obj's underlying member method code with example usage: obj.test_one_gram_fingerprint() and returns: unknown