Invoice entity before the model updates

Invoice.java

@Entity
public class Invoice extends ManagedEntity implements IManagedEntity
{
    @Attribute
    @Identifier
    protected Long invoiceId;

    @Attribute
    protected Date invoiceDate;

    @Attribute
    protected Date dueDate;

    @Attribute
    protected double amount;

    @Attribute
    protected String notes;

    @Relationship(type = RelationshipType.ONE_TO_ONE,
            inverse = "invoice",
            inverseClass = Payment.class,
            cascadePolicy = CascadePolicy.SAVE,
            fetchPolicy = FetchPolicy.EAGER)
    protected Payment payments;

    @Relationship(type = RelationshipType.MANY_TO_ONE,
            inverseClass = Account.class,
            inverse = "invoices")
    protected Account account;
}