What is the reason for making a nested class static in HashMap or LinkedList? [duplicate]

Question

In most of the cases I've seen that nested classes are static.

Lets take an example of Entry class in HashMap

static class Entry<K,V> implements Map.Entry<K,V> {
    final K key;
    V value;
    Entry<K,V> next;
    final int hash;

    .....
    .....
}

Or Entry class of LinkedList

private static class Entry<E> {
    E element;
    Entry<E> next;
    Entry<E> previous;

    .....
    .....
}

What I know so far about nested class is:

- A non-static nested class has full access to the members of the class 
  within which it is nested.

- A static nested class cannot invoke non-static methods or access non-
  static fields

My question is, what is the reason for making a nested class static in HashMap or LinkedList?

Update 1:

Following the already answer link I got an answer - Since And since it does not need 
access to LinkedList's members, it makes sense for it to be static - it's a much 
cleaner approach.

Also as @Kayaman pointed out: A nested static class doesn't require an instance of 
the enclosing class. This means that you can create a HashMap.Entry by itself, 
without having to create a HashMap first (which you might not need at all).

I think both these points answered my question. Thanks all for your input.

Answer 1

A nested static class doesn't require an instance of the enclosing class. This means that you can create a HashMap.Entry by itself, without having to create a HashMap first (which you might not need at all).