code: boolean addToBucket(State<S, L> state) {
          boolean first = bucket.isEmpty();
          bucket.pushBack(state);
          return first;
      }
docs: Adds a state to this blocks bucket.
  
  @param state
  the state to add.
  
  @return <code>true</code> iff this was the first state to be added to the bucket, <code>false</code> otherwise.