src/vs/workbench/api/common/extHostEditorTabs.ts/ExtHostEditorTabGroup/constructor
class ExtHostEditorTabGroup:	constructor(dto: IEditorTabGroupDto, proxy: MainThreadEditorTabsShape, activeGroupIdGetter: () => number | undefined) {
		this._dto = dto;
		this._activeGroupIdGetter = activeGroupIdGetter;
		// Construct all tabs from the given dto
		for (const tabDto of dto.tabs) {
			if (tabDto.isActive) {
				this._activeTabId = tabDto.id;
			}
			this._tabs.push(new ExtHostEditorTab(tabDto, this, () => this.activeTabId()));
		}
	}