.NET (Core and Framework)

Dim GlobalCollection as New Collection
Dim ChildCollection1 as New Collection
Dim tempCurrentCollection

GlobalCollection.Add(ChildCollection1, "Key1")

tempCurrentCollection = GlobalCollection("Key1")

tempCurrentCollection.Add(DataObjectA1, "DataA1")

public void GetSomeEntityBySomeParameter(int SomeParameter)
{
    try
    {
        // the Webservice object is auto-generated from the WSDL of the service and an instance
        // has been created in the constructor, as well as hooking up the event handler method to
        // receive the results
        this.Webservice.GetSomeEntityBySomeParameterAsync(SomeParameter);
    }
    
    catch(Exception e)
    {
        // error while sending the request
        // here comes code to do some logging and
        // handling if possible
    }
}

private void Webservice_GetSomeEntityBySomeParameterCompleted(object sender, SomeEventArgs e)
{
    SomeEntity Result = null;
    

    try
    {
        if(e.Result.ErrorReport != null)
        {
            // somme error has occurred on the server.
            // let's use the error info in the result to do some logging
            // and prepare some error info for the client
        }
        else
        {
            // let's convert the struct to an entity
            Result = ConvertSomeStructToEntity(e.Result.Value);
        }

        // *************** Big Mistake! ***************
        // this raises an event to notify the caller that the 
        // asynchronous call has been completed
        OnGetSomeEntityBySomeParameterFinished(Result);
    }
    
    catch(Exception e)
    {
        // something unexpected happened
        // little options to handle this, but let's
        // at least log all we can to provide some
        // info for debugging
    }
}