code: public boolean remove(DeliveryDelayableReference deliveryDelayableReference)
      {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(this, tc, "remove",
                          (deliveryDelayableReference == null ? "null" : "ObjId=" + deliveryDelayableReference.getID() + " ET=" + deliveryDelayableReference.getDeliveryDelayTime()));
  
          boolean reply = tree.delete(deliveryDelayableReference);
          if (reply)
          {
              size--;
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(this, tc, "remove", "reply=" + reply);
          return reply;
      }
docs: Remove a specific DeliveryDelayableReference from the delivery delay index. This method
  removes the object directly from the tree and does not use the iterator.
  It does not therefore require a prior call to next().
  
  @param deliveryDelayableReference the DeliveryDelayableReference to be removed.
  @return true if the object was removed from the index successfully.