public long getLocalLagFromRemoteInBytes() {
      return localLagFromRemoteInBytes;
    }
Shallow copy Constructor for {@link ExchangeMetadataResponse}, which copies all field references with exception
of 'missingStoreMessages' for which it creates new Set object.
@param other other {@link ExchangeMetadataResponse} object.
ambry-replication/src/main/java/com/github/ambry/replication/ReplicaThread.java