Retrieves and removes the head of the queue represented by this deque.
This method differs from {@link #poll poll} only in that it throws an
exception if this deque is empty.
<p>This method is equivalent to {@link #removeFirst() removeFirst}.
@return the head of the queue represented by this deque
@throws NoSuchElementException if this deque is empty
Retrieves and removes the head of the queue represented by this deque. This method differs from {@link #poll poll} only in that it throws an exception if this deque is empty.
<p>This method is equivalent to {@link #removeFirst() removeFirst}.
@return the head of the queue represented by this deque @throws NoSuchElementException if this deque is empty