pub trait BlobWriterProxyInterface: Send + Sync {
type GetVmoResponseFut: Future<Output = Result<BlobWriterGetVmoResult, Error>> + Send;
type BytesReadyResponseFut: Future<Output = Result<BlobWriterBytesReadyResult, Error>> + Send;
// Required methods
fn get_vmo(&self, size: u64) -> Self::GetVmoResponseFut;
fn bytes_ready(&self, bytes_written: u64) -> Self::BytesReadyResponseFut;
}