/**
 * Chunk array in parts
 * @param arr - array to chunk
 * @param chunk - number of chunks
 */
export declare class ArrayChunk {
    arr: any[];
    chunk: number;
    constructor(arr: any[], chunk?: number);
    /**
     * for each chunk
     * @param funct - chunk function
     */
    forEachChunk(funct: (ch: any[]) => void): void;
}
/**
 * bulk update data
 * @param docs - doc references to update
 * @param field - field to update
 * @param data - data to update
 */
export declare function bulkUpdate(docs: FirebaseFirestore.DocumentReference<FirebaseFirestore.DocumentData>[], data: any): Promise<null>;
/**
 * Bulk delete data
 * @param docs - doc references to delete
 * @param field - field to delete
 */
export declare function bulkDelete(docs: FirebaseFirestore.DocumentReference<FirebaseFirestore.DocumentData>[]): Promise<null>;