public boolean isEmpty() {
		return _tasks.isEmpty();
	}
Return {@code true} if there are no queue tasks available in {@code this}
task completion, {@code false} otherwise.

@return {@code true} if there are no queue tasks available in {@code this}
	       task completion, {@code false} otherwise
jenetics.incubator/src/main/java/io/jenetics/incubator/util/TaskCompletion.java