protected override void Execute(CodeActivityContext context)
{
IWorkflowContext workflowContext = context.GetExtension <IWorkflowContext>();
ParameterStack pstack = context.GetValue <ParameterStack>(this.Parameter);
string aliasName = context.GetValue <string>(this.AliasName);
string key = context.GetValue <string>(this.Key);
pstack.SetAlias(key, aliasName);
}