public async Task Start <TData, TStep>(TData data, Action <object> onCompletedWorkflow)
where TStep : Step
where TData : new()
{
var workflow = _workflowManager.CreateWorkflow(data);
var step = GetNextStep <TStep>();
var result = await workflow.Run <IWorkflow, TStep>(step);
var wf = (IWorkflow <object>)result;
onCompletedWorkflow.Invoke(wf.WorkflowData);
}