private void doRemove(ComponentPlaceholder placeholder) {
		windowPlaceholders.remove(placeholder);
		placeholder.setNode(null);
		if (windowPlaceholders.isEmpty()) {
			parent.removeNode(this);
		}
	}
Removes the component from this node, but not from the manager. Used when
the component is moved.  If component is active, it will remain active.
@param placeholder the object containing the component to be removed.
Ghidra/Framework/Docking/src/main/java/docking/ComponentNode.java