src/vs/workbench/browser/parts/editor/editorGroupView.ts/EditorGroupView/closeAllEditors
class EditorGroupView:	async closeAllEditors(options?: ICloseAllEditorsOptions): Promise<boolean> {
		if (this.isEmpty) {

			// If the group is empty and the request is to close all editors, we still close
			// the editor group is the related setting to close empty groups is enabled for
			// a convenient way of removing empty editor groups for the user.
			if (this.accessor.partOptions.closeEmptyGroups) {
				this.accessor.removeGroup(this);
			}

			return true;
		}

		// Check for confirmation and veto
		const veto = await this.handleCloseConfirmation(this.model.getEditors(EditorsOrder.MOST_RECENTLY_ACTIVE, options));
		if (veto) {
			return false;
		}

		// Do close
		this.doCloseAllEditors(options);

		return true;
	}