src/vs/workbench/api/common/extHostSCM.ts/ExtHostSCM/$setSelectedSourceControl
class ExtHostSCM:	$setSelectedSourceControl(selectedSourceControlHandle: number | undefined): Promise<void> {
		this.logService.trace('ExtHostSCM#$setSelectedSourceControl', selectedSourceControlHandle);

		if (selectedSourceControlHandle !== undefined) {
			this._sourceControls.get(selectedSourceControlHandle)?.setSelectionState(true);
		}

		if (this._selectedSourceControlHandle !== undefined) {
			this._sourceControls.get(this._selectedSourceControlHandle)?.setSelectionState(false);
		}

		this._selectedSourceControlHandle = selectedSourceControlHandle;
		return Promise.resolve(undefined);
	}