@Override
  public void close(ChannelHandlerContext ctx, ChannelPromise future) throws Exception {
    if (request != null) {
      logError(" : Channel closed while request in progress.");
    }
    super.close(ctx, future);
  }
Captures headers and other required info from request and responses, to make public access log entries
{@link PublicAccessLogger} assists in logging the required information
ambry-rest/src/main/java/com/github/ambry/rest/PublicAccessLogHandler.java