code: public void addTrace(final S state, final Word<I> input, final Word<O> output) {
          this.addTrace(this.nodeToObservationMap.get(state), input, output);
      }
docs: Store input/output information about a hypothesis state in the internal data structure.
  
  @param state
  the hypothesis state for which information should be stored
  @param input
  the input sequence applied when in the given state
  @param output
  the observed output sequence