code: private void removeNodeFromList(RepairQueueNode el) {
      // the head case
      //
      if (null == el.prev) {
        if (null != el.next) {
          this.head = el.next;
          this.head.prev = null;
          el=null;
        }
        else {
          // can't happen? yep. if there is only one element exists...
          this.head = null;
        }
      }
      // the tail case
      //
      else if (null == el.next) {
        if (null != el.prev) {
          el.prev.next = null;
        }
        else {
          // can't happen?
          throw new RuntimeException("Unrecognized situation here...");
        }
      }
      // all others
      //
      else {
        el.prev.next = el.next;
        el.next.prev = el.prev;
      }
  
    }
docs: Removes a node from the doubly linked list which backs the queue.
  
  @param el the element pointer.