@Override
	void close() {
		List<ComponentPlaceholder> list = new ArrayList<>(windowPlaceholders);
		Iterator<ComponentPlaceholder> it = list.iterator();
		while (it.hasNext()) {
			ComponentPlaceholder placeholder = it.next();
			placeholder.close();
		}
	}
Removes the component from this node (and the manager), but possibly keeps an empty object as
a placeholder.
@param placeholder the placeholder object to be removed.
@param keepEmptyPlaceholder flag indicating to keep a placeholder object.
Ghidra/Framework/Docking/src/main/java/docking/ComponentNode.java