public boolean hasError() {
		if (value instanceof ErrorMessage == false) {
			return false;
		}
		
		ErrorMessage probableError = (ErrorMessage) value;
		
		switch (probableError) {
		case EMPTY_STRUCTURE:
		case INDEX_OUT_OF_BOUNDS:
		case INVALID_ARGUMENT:
			return true;
		default:
			return false;
		}
	}