src/vs/workbench/contrib/debug/browser/debugSession.ts/DebugSession/setLastSteppingGranularity
class DebugSession:	private setLastSteppingGranularity(threadId: number, granularity?: DebugProtocol.SteppingGranularity) {
		const thread = this.getThread(threadId);
		if (thread) {
			thread.lastSteppingGranularity = granularity;
		}
	}