public int Add(
    object newObject
)

Public Function Add(
    newObject As Object
) As Integer

using System;
using System.Collections.Generic;
using System.Linq;
using DevExpress.Xpo;

namespace ConsoleApplication1 {
    public class Person : XPObject {
        public string Name {
            get { return fName; }
            set { SetPropertyValue(nameof(Name), ref fName, value); }
        }
        string fName;

        [Association("PersonAddresses"), Aggregated]
        public XPCollection<Address> Addresses {
            get { return GetCollection<Address>(nameof(Addresses)); }
        }
    }

    public class Address : XPObject {
        [Association("PersonAddresses")]
        public Person Owner {
            get { return fOwner; }
            set { SetPropertyValue(nameof(Owner), ref fOwner, value); }
        }
        Person fOwner;

        public string AddressInfo {
            get { return fAddressInfo; }
            set { SetPropertyValue(nameof(AddressInfo), ref fAddressInfo, value); }
        }
        string fAddressInfo;

    }

    class Program {
        static void Main(string[] args) {
            // Create a new instance of the Person class
            Person person = new Person() { Name = "Andrew Smith" };
            // Add an address for the person.
            Address address = new Address() { AddressInfo = "7654 Amsterdam Ave, New York, NY" };
            person.Addresses.Add(address);

            // Save the created Person object. The contents of the Addresses collection will be saved as well.
            person.Save();
            // Reload the object to verify if changes were saved.
            address.Reload();
            Console.WriteLine(address.AddressInfo);

            address.AddressInfo = "555 Harbor Way, Santa Barbara, CA";
            person.Save();
            // Reload the object to verify if changes were saved.
            address.Reload();
            Console.WriteLine(address.AddressInfo);

            Console.ReadKey();
        }
    }
}

Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports DevExpress.Xpo

Namespace ConsoleApplication1
    Public Class Person
        Inherits XPObject

        Public Property Name() As String
            Get
                Return fName
            End Get
            Set(ByVal value as String)
                SetPropertyValue(NameOf(Name), fName, value)
            End Set
        End Property
        Private fName As String

        <Association("PersonAddresses"), Aggregated> _
        Public ReadOnly Property Addresses() As XPCollection(Of Address)
            Get
                Return GetCollection(Of Address)(NameOf(Addresses))
            End Get
        End Property
    End Class

    Public Class Address
        Inherits XPObject

        <Association("PersonAddresses")> _
        Public Property Owner() As Person
            Get
                Return fOwner
            End Get
            Set(ByVal value as Person)
                SetPropertyValue(NameOf(Owner), fOwner, value)
            End Set
        End Property
        Private fOwner As Person

        Public Property AddressInfo() As String
            Get
                Return fAddressInfo
            End Get
            Set(ByVal value as String)
                SetPropertyValue(NameOf(AddressInfo), fAddressInfo, value)
            End Set
        End Property
        Private fAddressInfo As String

    End Class

    Friend Class Program
        Shared Sub Main(ByVal args() As String)
            ' Create a new instance of the Person class
            Dim person As New Person() With {.Name = "Andrew Smith"}
            ' Add an address for the person.
            Dim address As New Address() With {.AddressInfo = "7654 Amsterdam Ave, New York, NY"}
            person.Addresses.Add(address)

            ' Save the created Person object. The contents of the Addresses collection will be saved as well.
            person.Save()
            ' Reload the object to verify if changes were saved.
            address.Reload()
            Console.WriteLine(address.AddressInfo)

            address.AddressInfo = "555 Harbor Way, Santa Barbara, CA"
            person.Save()
            ' Reload the object to verify if changes were saved.
            address.Reload()
            Console.WriteLine(address.AddressInfo)

            Console.ReadKey()
        End Sub
    End Class
End Namespace

person.Save();
xpCollection1.Add(person);

DefaultAddress = new Address(employer.DefaultAddress);
    Addresses.Add(DefaultAddress);
}

lookup.Save();
    xpc2.Add(lookup);
}

person.Save()
xpCollection1.Add(person)

lookup.Save()
    xpc2.Add(lookup)
End If