Modify rowKey in prePut hook

[Daniel Gorgan - SKIN <da...@skin.ro>]

Hello,

I'm trying to implement something like autoIncrement in hbase's 
coprocessors.
If the rowKey I read in prePut is empty, I will generate a new one, be 
sure that it doesn't exists, and use that one. Also, the new key should 
return to client.
I'm trying to do this using coprocessors, I know I can do it on the 
client side, but I want to try it in coprocessors.

My question is, how can I modify the rowKey in prePut, if it's empty?

Thanks.