Question abour results from coroutine

   I created my coroutine and my iterator. I have my yield returns after every asynchronous query and I have my yield return corroutine at the end of the iterator method. 

Here is my problem. When the args.CompletedSuccessfully is reached there are 25 rows of the entity type I am returning. Here is my code. When the ResetStepTypesList is reached the variable is null. what am I doing wrong in the parameter to ResetStepTypesList method?

public void GetAvailableSteps()

{
var steps = Coroutine.Start(() => AvailableStepsSelector.RetrieveAvailableSteps(currentEvent));

steps.Completed += (sender, args) =>{
if (args.CompletedSuccessfully){

ResetStepTypesList(steps.Result as IEnumerable<EventStepType>);            //Results = 25 rows  

}
else{

}
};
}

public void ResetStepTypesList(IEnumerable<EventStepType> stepTypes) steps == null at this point

{
StepTypes.Clear();
stepTypes.ForEach(StepTypes.Add);
OnPropertyChanged("StepTypes");

}