Java ConcurrentLinkedDeque.removeFirst() is a method in the Java ConcurrentLinkedDeque class that removes and returns the first element of the deque. If the deque is empty, it throws a Java NoSuchElementException. This thread-safe operation is often used in multi-threaded environments where elements need to be processed in a first-in, first-out (FIFO) order. Introduced in Java 2004 with Java 5, removeFirst() is essential for managing deque operations safely in concurrent applications.

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