private String makeLoggingContext() {
    if (restRequest == null || restRequest.getRestRequestContext() == null) {
      return "";
    }
    String channelStr =
        ((NettyRequest.NettyRequestContext) restRequest.getRestRequestContext()).getChannel().toString();
    StringBuilder sb = new StringBuilder();
    sb.append('[');
    sb.append(channelStr);
    if (isEncryptionEnabled) {
      sb.append(", Encrypted");
    }
    return sb.append("]").toString();
  }
Return a string message that will be used as a context for logging;
@return
ambry-router/src/main/java/com/github/ambry/router/PutOperation.java