code: @Override
  	public void start () {
  		if (!lazy)
  			throw new UnsupportedOperationException("A non-lazy " + Include.class.getSimpleName() + " isn't meant to be run!");
  
  		if (child == null) {
  			// Lazy include is grafted at run-time
  			addChild(createSubtreeRootTask());
  		}
  	}
docs: The first call of this method lazily sets its child to the referenced subtree created through the
  {@link BehaviorTreeLibraryManager}. Subsequent calls do nothing since the child has already been set. A
  {@link UnsupportedOperationException} is thrown if this {@code Include} is eager.
  
  @throws UnsupportedOperationException if this {@code Include} is eager