code: public Term parse( String fullTextSearchExpression ) {
          CheckArg.isNotNull(fullTextSearchExpression, "fullTextSearchExpression");
          Tokenizer tokenizer = new TermTokenizer();
          TokenStream stream = new TokenStream(fullTextSearchExpression, tokenizer, false);
          return parse(stream.start());
      }
docs: Parse the full-text search criteria given in the supplied string.
  
  @param fullTextSearchExpression the full-text search expression; may not be null
  @return the term representation of the full-text search, or null if there are no terms
  @throws ParsingException if there is an error parsing the supplied string
  @throws IllegalArgumentException if the expression is null