src/vs/workbench/api/common/extHostNotebookKernels.ts/ExtHostNotebookKernels/registerKernelSourceActionProvider
class ExtHostNotebookKernels:	registerKernelSourceActionProvider(extension: IExtensionDescription, viewType: string, provider: vscode.NotebookKernelSourceActionProvider) {
		const handle = this._kernelSourceActionProviderHandlePool++;
		const that = this;

		this._kernelSourceActionProviders.set(handle, provider);
		this._logService.trace(`NotebookKernelSourceActionProvider[${handle}], CREATED by ${extension.identifier.value}`);
		this._proxy.$addKernelSourceActionProvider(handle, viewType);

		return {
			dispose: () => {
				this._kernelSourceActionProviders.delete(handle);
				that._proxy.$removeKernelSourceActionProvider(handle);
			}
		};
	}