src/vs/workbench/api/browser/mainThreadWebviewViews.ts/MainThreadWebviewsViews/$unregisterWebviewViewProvider
class MainThreadWebviewsViews:	public $unregisterWebviewViewProvider(viewType: string): void {
		const provider = this._webviewViewProviders.get(viewType);
		if (!provider) {
			throw new Error(`No view provider for ${viewType} registered`);
		}

		provider.dispose();
		this._webviewViewProviders.delete(viewType);
	}