src/vs/workbench/contrib/files/browser/views/openEditorsView.ts/OpenEditorsView/openEditor
class OpenEditorsView:	private openEditor(element: OpenEditor, options: { preserveFocus?: boolean; pinned?: boolean; sideBySide?: boolean; }): void {
		if (element) {
			this.telemetryService.publicLog2<WorkbenchActionExecutedEvent, WorkbenchActionExecutedClassification>('workbenchActionExecuted', { id: 'workbench.files.openFile', from: 'openEditors' });

			const preserveActivateGroup = options.sideBySide && options.preserveFocus; // needed for https://github.com/microsoft/vscode/issues/42399
			if (!preserveActivateGroup) {
				this.editorGroupService.activateGroup(element.group); // needed for https://github.com/microsoft/vscode/issues/6672
			}
			this.editorService.openEditor(element.editor, options, options.sideBySide ? SIDE_GROUP : element.group);
		}
	}