Java ConcurrentSkipListMap.containsKey() is a method in the Java ConcurrentSkipListMap class that checks if the specified key is present in the map. It provides thread-safe checking of keys in a map that maintains sorted order. Introduced in Java 2004 with Java 5, containsKey() is commonly used in concurrent applications where map lookups are necessary in a sorted, thread-safe map.

https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentSkipListMap.html