src/vs/workbench/contrib/debug/browser/debugSession.ts/DebugSession/clearThreads
class DebugSession:	clearThreads(removeThreads: boolean, reference: number | undefined = undefined): void {
		if (reference !== undefined && reference !== null) {
			const thread = this.threads.get(reference);
			if (thread) {
				thread.clearCallStack();
				thread.stoppedDetails = undefined;
				thread.stopped = false;

				if (removeThreads) {
					this.threads.delete(reference);
				}
			}
		} else {
			this.threads.forEach(thread => {
				thread.clearCallStack();
				thread.stoppedDetails = undefined;
				thread.stopped = false;
			});

			if (removeThreads) {
				this.threads.clear();
				ExpressionContainer.allValues.clear();
			}
		}
	}