boolean (int deltaUpToRoot, boolean allDeltasUpAreNull, int treeModCount) { if (myTree.getModCount() != treeModCount) return false; long newValue = packValues(deltaUpToRoot, allDeltasUpAreNull, treeModCount); long oldValue = cachedDeltaUpToRoot; return cachedDeltaUpdater.compareAndSet(this, oldValue, newValue); }