public static boolean isEventStream(Model model, MemberShape member) {
        return isEventStream(model.expectShape(member.getTarget()));
    }
Determines whether a given member targets an event stream.

@param model The model containing the member and its target.
@param member The member whose target should be checked.
@return True if the member targets a union with the streaming trait.
smithy-model/src/main/java/software/amazon/smithy/model/traits/StreamingTrait.java