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

		this._webviewViewProviders.deleteAndDispose(viewType);
	}