src/vs/workbench/api/common/extHostSCM.ts/ExtHostSCM/createSourceControl
class ExtHostSCM:	createSourceControl(extension: IExtensionDescription, id: string, label: string, rootUri: vscode.Uri | undefined): vscode.SourceControl {
		this.logService.trace('ExtHostSCM#createSourceControl', extension.identifier.value, id, label, rootUri);

		type TEvent = { extensionId: string };
		type TMeta = { extensionId: { classification: 'SystemMetaData'; purpose: 'FeatureInsight' } };
		this._telemetry.$publicLog2<TEvent, TMeta>('api/scm/createSourceControl', {
			extensionId: extension.identifier.value,
		});

		const handle = ExtHostSCM._handlePool++;
		const sourceControl = new ExtHostSourceControl(extension, this._proxy, this._commands, id, label, rootUri);
		this._sourceControls.set(handle, sourceControl);

		const sourceControls = this._sourceControlsByExtension.get(ExtensionIdentifier.toKey(extension.identifier)) || [];
		sourceControls.push(sourceControl);
		this._sourceControlsByExtension.set(ExtensionIdentifier.toKey(extension.identifier), sourceControls);

		return sourceControl;
	}