Bank, Loanable interface

/*
 * Loanable Interface
 * That is the customer requirements from us
 * Do not change it without customer confirmation
 */
package BankInterfaces;

import BankExceptions.BankLoanException;

public interface Loanable {
    /*
     * Take a loan from the bank return true only if customer don't have loan
     */
    boolean giveLoan(double sum, int payments) throws BankLoanException;

    /*
     * pay one payment for the loan
     */
    boolean loanPaymentReturn();

    /*
     * return a string with monthly loan return plan
     */
    String loanReturnByMonth();
}