code: public PatternTokenizer setSyntaxCharacters(UnicodeSet syntaxCharacters) {
          this.syntaxCharacters = (UnicodeSet) syntaxCharacters.clone();
          needingQuoteCharacters = null;
          return this;
      }
docs: Sets the characters to be interpreted as syntax characters in parsing, eg new UnicodeSet("[:pattern_syntax:]")
  @param syntaxCharacters Characters to be set as syntax characters.
  @return A PatternTokenizer object in which characters are specified as syntax characters.