`channelRead0` Is a weird name. 

https://github.com/netty/netty/issues/1590
https://github.com/netty/netty/blob/4.0/transport/src/main/java/io/netty/channel/SimpleChannelInboundHandler.java#L116

Looks like they just wanted an overloaded abstract method and added 0 to the end of it.