code: public BehaviorTree<E> parse (Reader reader, E object) {
  		btReader.parse(reader);
  		return createBehaviorTree(btReader.root, object);
  	}
docs: Parses the given reader.
  @param reader the reader to parse
  @param object the blackboard object. It can be {@code null}.
  @return the behavior tree
  @throws SerializationException if the reader cannot be successfully parsed.