@sap/generator-fiori/generators/fe-fpm-writer/templates/controller-extension/ControllerExtension.d.ts

Create an SAPUI5 application using SAP Fiori elements or a freestyle approach

/**
 * Helper to be able to define how to get the page specific extension API when writing a controller extension.
 */
declare module 'sap/ui/core/mvc/ControllerExtension' {
    export default class ControllerExtension<API> {
        static overrides: unknown;
        base: {
            getExtensionAPI(): API;
        }
    }
}