src/vs/workbench/browser/parts/compositePart.ts/CompositePart/removeComposite
class CompositePart:	protected removeComposite(compositeId: string): boolean {
		if (this.activeComposite?.getId() === compositeId) {
			return false; // do not remove active composite
		}

		this.mapCompositeToCompositeContainer.delete(compositeId);
		this.mapActionsBindingToComposite.delete(compositeId);
		const compositeItem = this.instantiatedCompositeItems.get(compositeId);
		if (compositeItem) {
			compositeItem.composite.dispose();
			dispose(compositeItem.disposable);
			this.instantiatedCompositeItems.delete(compositeId);
		}

		return true;
	}