Wanted to create a custom group function

[dhaval deshpande]

Hi,
       i wanted to create a custom group function in pig. I was not sure
where to start from. I check some documentation online but couldnt figure
out. I also checked on wiki and it says I need to extend a abstract class
GroupFunc. and when i try to do that it says GroupFunc class doesnt not
exist. Please help me where do I start from.

Thanks,
Dhaval.