package java.util.concurrent;

import java.io.Serializable;
import java.util.AbstractMap;
import java.util.Map;
import java.util.Set;

public class ConcurrentHashMap<K,V> extends AbstractMap<K,V> implements ConcurrentMap<K,V>, Serializable {
	public static void main(String[] args) {
		System.out.printf("ConcurrentHashMap");
	}

	public Set<Map.Entry<K,V>> entrySet() {
		return null;
	}

	public boolean replace(K key, V oldValue, V newValue) {
		return true;
	}

	public V replace(K key, V value) {
		return null;
	}
	public V remove(Object o) { return null; }

	public boolean remove(Object key, Object value) { return false; }

	public V putIfAbsent(K key, V value) {
		return null;
	}
}

@@ -235,16 +235,17 @@
 zable %7B%0A
+%0A
 %09public 
@@ -320,24 +320,281 @@
 hMap%22);%0A%09%7D%0A%0A
+%09public ConcurrentHashMap() %7B%0A%09%7D%0A%0A%09public ConcurrentHashMap(Map%3C? extends K, ? extends V%3E m) %7B%0A%09%7D%0A%0A%09public ConcurrentHashMap(int initialCapacity) %7B%0A%09%7D%0A%0A%09public V put(K key, V value) %7B%0A%09%09throw new RuntimeException(%22Not implemented %3CConcurrentHashMap%3E%22);%0A%09%7D%0A%0A
 %09public Set%3C

Implement concurrent interface