How to merge custom Contact Facets

MergeContactFacets.cs

public static void DeepCopyFacet(IFacet source, IFacet destination)
{
    Assert.ArgumentNotNull((object)source, "source");
    Assert.ArgumentNotNull((object)destination, "destination");
    CopyElement((IElement)source, (IElement)destination);
}

private static void CopyElement(IElement source, IElement destination)
{
    foreach (IModelMember modelMember in (IEnumerable<IModelMember>)source.Members)
    {
        IModelAttributeMember modelAttributeMember = modelMember as IModelAttributeMember;
        if (modelAttributeMember != null)
        {
            ((IModelAttributeMember)destination.Members[modelMember.Name]).Value 
                = modelAttributeMember.Value;
        }
        else
        {
            IModelDictionaryMember dictionaryMember1 = modelMember as IModelDictionaryMember;
            if (dictionaryMember1 != null)
            {
                IModelDictionaryMember dictionaryMember2 
                    = (IModelDictionaryMember)destination.Members[modelMember.Name];
                    
                foreach (string key in (IEnumerable<string>)dictionaryMember1.Elements.Keys)
                {
                    IElement destination1 = dictionaryMember2.Elements.Create(key);
                    CopyElement(dictionaryMember1.Elements[key], destination1);
                }
            }
            else
            {
                IModelCollectionMember collectionMember1 = modelMember as IModelCollectionMember;
                if (collectionMember1 != null)
                {
                    IModelCollectionMember collectionMember2 
                        = (IModelCollectionMember)destination.Members[modelMember.Name];
                        
                    for (int index = 0; index < collectionMember1.Elements.Count; ++index)
                    {
                        IElement destination1 = collectionMember2.Elements.Create();
                        CopyElement(collectionMember1.Elements[index], destination1);
                    }
                }
                else
                {
                    IModelElementMember modelElementMember1 = modelMember as IModelElementMember;
                    if (modelElementMember1 != null)
                    {
                        IModelElementMember modelElementMember2 
                            = (IModelElementMember)destination.Members[modelElementMember1.Name];
                        CopyElement(modelElementMember1.Element, modelElementMember2.Element);
                    }
                }
            }
        }
    }
}