So I am continuing my previous code, in conclusion I am doing a bank (as a work for university). So, now the class name is CuentaBancaria.java. The block code is the following:

package fp2.poo.pfpooWFG8420;


import fp2.poo.utilidades.CuentaBancariaInterfaz;
import fp2.poo.utilidades.SaldoInterfaz;
import fp2.poo.utilidades.Excepciones.OperacionNoPermitidaExcepcion;
import  fp2.poo.pfpooWFG8420.Titular;
import fp2.poo.utilidades.TelefonoInterfaz;
import fp2.poo.utilidades.CorreoElectronicoInterfaz;
import  fp2.poo.pfpooWFG8420.NumeroDeCuenta;
import  fp2.poo.pfpooWFG8420.Saldo;

/**
 * Implementacion de la clase CuentaBancaria a partir de una
 * interfaz
 *
 */

public class CuentaBancaria implements CuentaBancariaInterfaz {

    // Atributos

    private Saldo saldo;
    private NumeroDeCuenta numeroDeCuenta;
    private Titular titular;
    
    // Constructor

     /**
     * Constructor de CuentaBancaria
     *
     * @see CuentaBancaria#CuentaBancaria()
     */
    public CuentaBancaria() {
    this.saldo = new Saldo();
    this.numeroDeCuenta = new NumeroDeCuenta();
    this.titular = new Titular();
    }
    
    // Metodos

    // Hereda comentarios de documentacion
    public void setSaldo(Saldo saldo) {
    this.saldo = saldo;
    }

    // Hereda comentarios de documentacion
    public Saldo getSaldo() {
    return this.saldo;
    }

    // Hereda comentarios de documentacion
    public void setNumeroDeCuenta(NumeroDeCuenta numeroDeCuenta) {
    this.numeroDeCuenta = numeroDeCuenta;
    }

    // Hereda comentarios de documentacion
    public NumeroDeCuenta getNumeroDeCuenta() {
    return this.numeroDeCuenta;
    }

    // Hereda comentarios de documentacion
    public void setTitular(Titular titular) {
    this.titular = titular;
    }

    // Hereda comentarios de documentacion
    public Titular getTitular() {
    return this.titular;
    }

    
}

I recicled this from another work I did weeks ago, and modified it a little bit, with the needed things. So I compiled it, I do not know yet If I have code mistakes, and the MATE Terminal put the following error:
CuentaBancaria is not abstract and does not override abstract method setTitular(TitularInterfaz) in CuentaBancariaInterfaz
public class CuentaBancaria implements CuentaBancariaInterfaz {

So what I tried was fixing it the same way I did previously with another class which was changing some stuff, and looking If there were any destinations put wrongly. I expected that it was gonna be that, and indeed it was partially, the other errors I fixed it because the makefile I made, I forgot to put ./bin/fp2/poo/pfpooWFG8420/Saldo.class, though this is not that so I do not know a way that can fix it everytime.

I will keep try to and If I fix it, I will post it. Thank you for looking on it if you do so, and thanks for the help!