// Simplified internal structure Node<K,V>[] table;
// Node class representing each entry in the map static class Node<K,V> extends HashMap.Node<K,V> Node<K,V> next;
// Simplified internal structure Node<K,V>[] table;
// Node class representing each entry in the map static class Node<K,V> extends HashMap.Node<K,V> Node<K,V> next; java hashmap under the hood