src/vs/workbench/browser/parts/editor/editorGroupView.ts/EditorGroupView/copyEditors
class EditorGroupView:	copyEditors(editors: { editor: EditorInput; options?: IEditorOptions }[], target: EditorGroupView): void {

		// Optimization: knowing that we move many editors, we
		// delay the title update to a later point for this group
		// through a method that allows for bulk updates but only
		// when moving to a different group where many editors
		// are more likely to occur.
		const internalOptions: IInternalMoveCopyOptions = {
			skipTitleUpdate: this !== target
		};

		for (const { editor, options } of editors) {
			this.copyEditor(editor, target, options, internalOptions);
		}

		// Update the title control all at once with all editors
		// in target if the title update was skipped
		if (internalOptions.skipTitleUpdate) {
			const copiedEditors = editors.map(({ editor }) => editor);
			target.titleAreaControl.openEditors(copiedEditors);
		}
	}