Function render_upload_operator 

fn render_upload_operator<'scope, T>(
    scope: Scope<'scope, Timestamp>,
    connection_context: ConnectionContext,
    aws_connection: AwsConnection,
    connection_id: CatalogItemId,
    connection_details: S3UploadInfo,
    sink_id: GlobalId,
    input_collection: StreamVec<'scope, Timestamp, Vec<ColumnationStack<((Row, ()), Timestamp, Diff)>>>,
    up_to: Antichain<Timestamp>,
    start_stream: StreamVec<'scope, Timestamp, Result<(), String>>,
    params: CopyToParameters,
    output_batch_count: u64,
) -> (StreamVec<'scope, Timestamp, Result<u64, String>>, PressOnDropButton)
where
    T: CopyToS3Uploader,

Renders the upload operator, which waits on the start_stream to ensure initialization is complete and then handles the uploads to S3. Returns a completion_stream which contains 1 event per worker of the result of the upload operation, either an error or the number of rows uploaded by the worker.

The input_collection must be a stream of chains, partitioned and exchanged by the row’s hash modulo the number of batches.