message: Store an empty engine in the case that dynamic engine creation fails. The next time the same input shape appears, we will retrieve the empty engine which tells us to not rebuild the same failing engine again.
diff: @@ -633,6 +633,9 @@ EngineContext* TRTEngineOp::GetEngine(
  }
  LOG(WARNING) << "Engine creation for batch size " << batch_size
  << " failed " << status;
  + // Store an empty engine here so we don't try to build the same engine
  + // again.
  + cache.emplace(engine_input_shapes, empty_context);
  return &empty_context;
  }
  VLOG(1) << "Conversion is done";
  