code: @Override
      public Acceptance lookup(Word<? extends I> word) {
          State s = getState(word);
          if (s == null) {
              return Acceptance.DONT_KNOW;
          }
          return s.getAcceptance();
      }
docs: Checks the ternary acceptance status for a given word.
  
  @param word
  the word to check
  
  @return the acceptance status for the given word