src/vs/workbench/api/browser/viewsExtensionPoint.ts/ViewsExtensionHandler/removeViews
class ViewsExtensionHandler:	private removeViews(extensions: readonly IExtensionPointUser<ViewExtensionPointType>[]): void {
		const removedExtensions: Set<string> = extensions.reduce((result, e) => { result.add(ExtensionIdentifier.toKey(e.description.identifier)); return result; }, new Set<string>());
		for (const viewContainer of this.viewContainersRegistry.all) {
			const removedViews = this.viewsRegistry.getViews(viewContainer).filter(v => (v as ICustomViewDescriptor).extensionId && removedExtensions.has(ExtensionIdentifier.toKey((v as ICustomViewDescriptor).extensionId)));
			if (removedViews.length) {
				this.viewsRegistry.deregisterViews(removedViews, viewContainer);
			}
		}
	}