src/vs/workbench/api/common/extHostNotebookKernels.ts/ExtHostNotebookKernels/$cellExecutionChanged
class ExtHostNotebookKernels:	$cellExecutionChanged(uri: UriComponents, cellHandle: number, state: NotebookCellExecutionState | undefined): void {
		const document = this._extHostNotebook.getNotebookDocument(URI.revive(uri));
		const cell = document.getCell(cellHandle);
		if (cell) {
			this._onDidChangeCellExecutionState.fire({
				cell: cell.apiCell,
				state: state ? extHostTypeConverters.NotebookCellExecutionState.to(state) : ExtHostNotebookCellExecutionState.Idle
			});
		}
	}