private void removeHandlers(ChannelHandlerContext ctx) {
    ChannelPipeline p = ctx.pipeline();
    p.remove(SaslChallengeDecoder.class);
    p.remove(this);
  }
@param saslPromise {@code true} if success, {@code false} if server tells us to fallback to
                   simple.
hbase-client/src/main/java/org/apache/hadoop/hbase/security/NettyHBaseSaslRpcClientHandler.java