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  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.concurrent.ConcurrentHashMap;
  4.  
  5. /* Name of the class has to be "Main" only if the class is public. */
  6. class Ideone
  7. {
  8. 	public static void main (String[] args) throws java.lang.Exception
  9. 	{
  10. 		ConcurrentHashMap<Object, Object> m = new ConcurrentHashMap<>();
  11. 		System.out.println(m.putIfAbsent(new Object(), new Object()));
  12. 	}
  13. }
Success #stdin #stdout 0.1s 320512KB
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https://ideone.com/l8VejJ
language:
Java (HotSpot 12)
created:
9 years ago
visibility:
public

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