import { TemplateEngineEnum } from '../../interfaces/template.types';
import { TemplateEngine } from '../template-engine';
import type { ConfigureOptions } from 'nunjucks';
import { CustomEngineOptions, EngineOptions } from '../../interfaces/module-config.interface';
export declare class NunjucksEngine extends TemplateEngine {
    private options?;
    private customOptions?;
    static engineName: TemplateEngineEnum;
    private env;
    constructor(options?: EngineOptions<ConfigureOptions>, customOptions?: CustomEngineOptions);
    initNunjucks(): void;
    render(content: string, data?: Record<string, any>): Promise<string>;
    validate(content: string): Promise<boolean>;
    registerFilter(name: string, filter: (...args: any[]) => any): void;
}