class DataProviderEvents<SourceType> extends EventGroup { 
  var eventOne : Event< DataEvent<TypeOne> -> SourceType -> Void >;
  var eventTwo : Event< DataEvent<TypeTwo> -> SourceType -> Void >;
}

class SomeDataProviderDispatcher
{
  var events : DataProviderEvents<SomeDataProviderDispatcher>;
}

class MyListener
{
  function onEventOne( d:DataEvent<TypeOne>, src:SomeDataProviderDispatcher );
}