export declare class HelperService {
    constructor();
    queryString(jsonData: any): string;
    formatCode(prefix: any): string;
    generateGuid(): string;
    getTimestamp(): number;
    copy(obj: any): any;
    preventPrecisionNumber(number: any): number;
    roundWithDecimals(value: number, precision?: number): number;
    formatCustomerAddress(customer: any): string;
    isValidTransactionDate(date?: Date | string): boolean;
    calculateVatAmount(vat: number, unitPrice: number): number;
}