private void registerPlaceholder(ComponentPlaceholder placeholder) {

		ComponentProvider provider = placeholder.getProvider();
		String owner = provider.getOwner();
		PlaceholderSet placeholderSet = ownerToPlaceholderMap.get(owner);
		if (placeholderSet == null) {
			placeholderSet = new PlaceholderSet(this);
			ownerToPlaceholderMap.put(owner, placeholderSet);
		}

		placeholderSet.placeholderUsed(provider, placeholder);
	}
Moves all the actions associated with the old placeholder into the new placeholder.
@param oldPlaceholder the old component placeholder being replaced.
@param newPlaceholder the new component placeholder.
Ghidra/Framework/Docking/src/main/java/docking/PlaceholderManager.java