protected async Task <IOperationResult> PerformConcate(ConcatenationMode mode, string key, ulong cas, ArraySegment <byte> data) { try { var op = opFactory.Concat(mode, keyTransformer.Transform(key), data, cas); await cluster.Execute(op).ConfigureAwait(false); return(op.Result); } catch (IOException e) { return(new BinaryOperationResult().FailWith(e)); } }