code: public boolean addToBucket(State<S, EP> state) {
          boolean first = false;
  
          if (bucket.isEmpty()) {
              first = true;
          }
          bucket.pushBack(state);
  
          return first;
      }
docs: Adds a state to this label's bucket.
  
  @param state
  the state to be added to the bucket.
  
  @return <code>true</code> if this is the first state to be added to the bucket, <code>false</code> otherwise.