pub trait CommonProxyInterface: Send + Sync {
type QueryResponseFut: Future<Output = Result<(BlockInfo, u64), Error>> + Send;
type QueueResponseFut: Future<Output = Result<(i32, BlockOp), Error>> + Send;
// Required methods
fn query(&self) -> Self::QueryResponseFut;
fn queue(&self, txn: BlockOp) -> Self::QueueResponseFut;
}