@Override public int hashCode() { int result = id; result = 31 * result + (name != null ? name.hashCode() : 0); result = 31 * result + (surname != null ? surname.hashCode() : 0); result = 31 * result + hoursWorkedThisMonth; result = 31 * result + (state != null ? state.hashCode() : 0); result = 31 * result + (currentCity != null ? currentCity.hashCode() : 0); result = 31 * result + (currentTruck != null ? currentTruck.hashCode() : 0); return result; }