Public Overloads Shared Function Start( _
   ByVal coroutine As Func(Of IEnumerable(Of INotifyCompleted)), _
   Optional ByVal completedHandler As Action(Of CoroutineOperation) _
) As CoroutineOperation

Dim coroutine As Func(Of IEnumerable(Of INotifyCompleted))
Dim completedHandler As Action(Of CoroutineOperation)
Dim value As CoroutineOperation
 
value = Coroutine.Start(coroutine, completedHandler)

public static CoroutineOperation Start( 
   Func<IEnumerable<INotifyCompleted>> coroutine,
   Action<CoroutineOperation> completedHandler
)

public:
static CoroutineOperation^ Start( 
   Func<IEnumerable<INotifyCompleted^>^>^ coroutine,
   Action<CoroutineOperation^>^ completedHandler
) 

public void CoroutineSample() {
   // Note that a new EM is not required for a Coroutine, we show it here for completeness.
   _mgr = new DomainModelEntityManager();
   
   // Start some serial async operations.
   var op = Coroutine.Start(SampleActions);
   
   // Listen for completion.
   op.Completed += (s, e) => {
     if (e.HasError) {
       MessageBox.Show(e.Error.Message);
       e.MarkErrorAsHandled();
     } 
   };
 }
 
 private EntityManager _mgr;

 // A block of asynchronous actions.
 private IEnumerable<INotifyCompleted> SampleActions() {

   // Start a query for all customers in specified country, yield when async op completes.
   var op1 = _mgr.Customers.Where(c => c.Country == "UK").ExecuteAsync();
   yield return op1;

   // Resume execution here when op1 completes.  Take a look at results from 1st query
   TraceFns.WriteLine("Customer count = " + op1.Results.Count().ToString());

   // Perform another async quuery for all employees.
   var op2 = _mgr.Employees.ExecuteAsync();
   yield return op2;

   // Resume execution here when op2 completes.  See what it returned.
   TraceFns.WriteLine("Employee count = " + op2.Results.Count().ToString());
 }    
 
 /***************************************************************************************/
 // Sample 2 - passing arguments to an iterator
 
 public void CoroutineSample2a() {
   // Note that a new EM is not required for a Coroutine, we show it here for completeness.
   _mgr = new DomainModelEntityManager();

   // Start some serial async operations.
   var op = Coroutine.Start(() => SampleActions2("USA"));
   
   // Listen for completion.
   op.Completed += (s, e) => {
     if (e.HasError) {
       MessageBox.Show(e.Error.Message);
       e.MarkErrorAsHandled();
     } 
   };
 }
 
 private IEnumerable<INotifyCompleted> SampleActions2(String country) {

   // Start a query for all customers in specified country, yield when async op completes.
   var op1 = _em1.Customers.Where(c => c.Country == country).ExecuteAsync();
   yield return op1;

   // Resume execution here when op1 completes.  Take a look at results from 1st query
   TraceFns.WriteLine("Customer count = " + op1.Results.Count().ToString());

   // Perform another async quuery for all employees.
   var op2 = _em1.Employees.ExecuteAsync();
   yield return op2;

   // Resume execution here when op2 completes.  See what it returned.
   TraceFns.WriteLine("Employee count = " + op2.Results.Count().ToString());
 }