retrieves and removes the head of this queue . concode_field_sep HashMap<String,LinkedList<T>> queueMap concode_elem_sep LinkedList<LinkedList<T>> queueList concode_field_sep boolean add concode_elem_sep boolean containsAll concode_elem_sep void clear concode_elem_sep boolean isEmpty concode_elem_sep List<T> toList concode_elem_sep String getQueueId concode_elem_sep T remove concode_elem_sep boolean remove concode_elem_sep T peek concode_elem_sep boolean offer concode_elem_sep boolean removeAll concode_elem_sep boolean contains concode_elem_sep Iterator<T> iterator concode_elem_sep int size concode_elem_sep boolean addAll concode_elem_sep Object[] toArray concode_elem_sep T2[] toArray concode_elem_sep T element concode_elem_sep boolean retainAll
T function ( ) { try { return remove ( ) ; } catch ( NoSuchElementException loc0 ) { return null ; } }