import { Observable } from 'rxjs';
export declare abstract class TranslationService {
    /**
     * Translates given key with options.
     * If key is missing, it tries to load the chunk and emits a value when chunk is loaded.
     * If key is missing after loaded chunk, a fallback value is emitted
     *
     * @param key translation key
     * @param options values for interpolation in translation
     * @param whitespaceUntilLoaded if true, immediately emits a non-breaking space
     */
    translate: (key: string, options?: any, whitespaceUntilLoaded?: boolean) => Observable<string>;
    /**
     * Loads chunks with translations
     *
     * @param chunkNames array of chunk names to be loaded
     */
    loadChunks: (chunkNames: string | string[]) => Promise<any>;
}