code: public Object tryGet() {
          Object o = null;
  
          if (head != null) {
              o = head.getContents();
              head = head.getNext();
              count--;
  
              if (head == null) {
                  tail = null;
                  count = 0;
              }
          }
  
          return o;
      }
docs: attempt to retrieve message from queue head