Function create_error_streaming 

pub async fn create_error_streaming<H: McpHandler>(
    client: &HttpClient,
    params: ErrorCreateParams,
    handler: H,
) -> Result<(impl Stream<Item = Result<ErrorResponse, HttpError>> + Send + Unpin + 'static + use<H>, Notifier), HttpError>

Creates an error response with streaming. Returns (Stream<Chunk>, Notifier); see [crate::agent::completions::http::create_agent_completion_streaming] for the demux + handler semantics.