I am defining variable with type hint and initialize it with empty value like this:

 accumulator: OrderedDict[str, set[str]] = {}

but this gives warning message

Assign to "accumulator" a value of type "OrderedDict[str, set[str]]" instead of "dict" or update its type hint.
Expected type 'OrderedDict[str, set[str]]', got 'dict' instead 

How to initialize this variable correctly?

thanks