Confusion with the streaming example in section 13.1 of IDL v2

Link. Example as of writing:

operation StreamingOperation {
    input: StreamingOperationInput
    output: StreamingOperationOutput
}

@input
structure StreamingOperationInput {}

@output
structure StreamingOperationOutput {
    @required
    streamId: String
    output: StreamingBlob
}

@streaming
blob StreamingBlob

I’m confused because:

1. Smithy IDL v2 introduces a change where members targeting streaming blobs now MUST have @default or @required. However, output in the example above does not have any of the two traits attached.
2. In IDL v1 there is a restriction on the streaming trait that says:

If a service supports a protocol that supports the httpPayload trait, any member that targets a streaming blob must also be marked as @httpPayload.

However, this restriction does not appear in IDL v2. Is that intentional? The Smithy library is still enforcing it for IDL v2 models:

= Member com.amazonaws.simple#AnOperationInput$streamingBlob referencing @streaming shape com.amazonaws.simple#StreamingBlob must have the @httpPayload trait, as service com.amazonaws.simple#SimpleService has a protocol that supports @httpPayload.

1. The example is confusing because you can’t send both a string (streamId) and a streaming blob (output) in the same HTTP message body (?). I acknowledge that in another application-level protocol sending both pieces of data might be possible (which one?), but if you want to keep the example as-is, I think it would be better to call out immediately below it that it’s not realizable in HTTP.

[mtdowling]

The streaming blob has a default value assigned using = "" which is exactly the same as @default(""). I’ll add an HTTP binding for the streamId member. (Edit) Actually, we can just remove the streamId member. I don’t think it’s needed for the example.

[mtdowling]

Oh! You’re right. I completely glossed over that this targeted a blob. The example is theoretically fine as is, but doesn’t work with any existing protocols, so I’ll change it.