The `ForceUpdate` method is a public instance method of the `CommentUI` class within the `Editor.NodeEditor` namespace. This method is used to trigger an immediate update of the comment UI element. It ensures that any changes made to the comment are reflected in the UI without waiting for the next scheduled update cycle.

To use the `ForceUpdate` method, you must have an instance of the `CommentUI` class. Once you have this instance, you can call the method directly to force an update of the comment UI. This is particularly useful when you need to ensure that the UI reflects changes immediately after they are made.

// Assuming you have an instance of CommentUI
CommentUI commentUI = new CommentUI();

// Force an immediate update of the comment UI
documentUI.ForceUpdate();