code: static int flush(char[] accum, int finger, List tokens) {
      if (finger > 0) {
        char[] token = new char[finger];
        System.arraycopy(accum,0, token,0, finger);
        tokens.add(token);
      }
      return 0;
    }
docs: Parsing subroutine to flush the accumulated characters to the tokens list as a char[]
  
  @param accum the char[] being used to accumulate characters
  @param finger the next position in the buffer (used as a length here)
  @param tokens the List of tokens being accumulated (mutated by this method)
  @return the new value of finger, which is always 0