Retrieves, but does not remove, the head of this queue. This method differs from {@link #peek peek} only in that it throws an exception if this queue is empty.
@return the head of this queue @throws NoSuchElementException if this queue is empty
See Implementation
Retrieves, but does not remove, the head of this queue. This method differs from {@link #peek peek} only in that it throws an exception if this queue is empty.
@return the head of this queue @throws NoSuchElementException if this queue is empty