code: protected boolean addToPath(GP path, ST segment) {
  		if (this.pathFactory != null) {
  			return this.pathFactory.addToPath(path, segment);
  		}
  		assert path != null;
  		assert segment != null;
  		try {
  			return path.add(segment);
  		} catch (Throwable e) {
  			throw new IllegalStateException(e);
  		}
  	}
docs: Add the given segment into the given path.
  
  <p>By default this function invokes the path factory
  passed as parameter of the constructor.
  
  @param path is the path to build.
  @param segment is the segment to add.
  @return <code>true</code> if the segment was added;
  otherwise <code>false</code>.