<ExtensionAttribute()>
Public Overloads Shared Function ExecuteAsync( _
   ByVal query As IEntityQuery, _
   ByVal userCallback As Action(Of EntityQueryOperation), _
   Optional ByVal userState As Object _
) As EntityQueryOperation

Dim query As IEntityQuery
Dim userCallback As Action(Of EntityQueryOperation)
Dim userState As Object
Dim value As EntityQueryOperation
 
value = EntityQueryExtensions.ExecuteAsync(query, userCallback, userState)

[ExtensionAttribute()]
public static EntityQueryOperation ExecuteAsync( 
   IEntityQuery query,
   Action<EntityQueryOperation> userCallback,
   object userState
)

[ExtensionAttribute()]
public:
static EntityQueryOperation^ ExecuteAsync( 
   IEntityQuery^ query,
   Action<EntityQueryOperation^>^ userCallback,
   Object^ userState
) 

DomainModelEntityManager mgr = new DomainModelEntityManager();

var query = mgr.Customers.Where(c => c.Country == "UK");
query.ExecuteAsync(op => {
  var customers = op.Results;
});