code: public char match(String str1, String str2) {
          if (null == str1 || null == str2 || 0 == str1.length() || 0 == str2.length()) {
              return IMappingElement.IDK;
          }
          float sim = 1 - (float) getLevenshteinDistance(str1, str2) / java.lang.Math.max(str1.length(), str2.length());
          if (threshold <= sim) {
              return IMappingElement.EQUIVALENCE;
          } else {
              return IMappingElement.IDK;
          }
      }
docs: Computes the relation with optimized edit distance matcher.
  
  @param str1 source input string
  @param str2 target input string
  @return synonym or IDK relation