code: @Override
      public boolean matchesIndexValue(int v) {
          if (pattern.length() == 0) {
              return true;
          }
          int c = UTF16.charAt(pattern, 0);
          UnicodeMatcher m = data.lookupMatcher(c);
          return (m == null) ? ((c & 0xFF) == v) : m.matchesIndexValue(v);
      }
docs: Implement UnicodeMatcher