import { database } from "firebase-admin";
import DataSnapshot = database.DataSnapshot;
export declare class FirebaseDataService {
    protected db: database.Database;
    protected constructor(db: database.Database);
    getList(path: string): Promise<any[]>;
    updateObject(path: string, obj: any): Promise<void>;
    getObject(path: string): Promise<any>;
    setObject(path: string, obj: any): Promise<void>;
    findAllObjectsBy(path: string, propertyName: string, value: number | string | boolean | null): Promise<any[]>;
    static handleList(snapshot: DataSnapshot): any[];
    static convertObjectToList(obj: any): any[];
    static mixKey(obj: any | undefined, key: string | null | undefined): any;
}