src/vs/workbench/contrib/notebook/browser/services/notebookKernelServiceImpl.ts/NotebookKernelService/registerKernelSourceActionProvider
class NotebookKernelService:	registerKernelSourceActionProvider(viewType: string, provider: IKernelSourceActionProvider): IDisposable {
		const providers = this._kernelSourceActionProviders.get(viewType) ?? [];
		providers.push(provider);
		this._kernelSourceActionProviders.set(viewType, providers);
		this._onDidChangeSourceActions.fire({ viewType: viewType });

		return toDisposable(() => {
			const providers = this._kernelSourceActionProviders.get(viewType) ?? [];
			const idx = providers.indexOf(provider);
			if (idx >= 0) {
				providers.splice(idx, 1);
				this._kernelSourceActionProviders.set(viewType, providers);
			}
		});
	}