The creator of the class explicitly marked it that way because they did not want you to extend it. Probably to avoid having access to its protected members. But I can only guess as to their intentions. Generally, you have to use such a class with composition (create one and put it in a private field in your own class) rather than inheritance.
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The creator of the class explicitly marked it that way because they did not want you to extend it. Probably to avoid having access to its protected members. But I can only guess as to their intentions. Generally, you have to use such a class with composition (create one and put it in a private field in your own class) rather than inheritance.