RelBuilder examples

[Abbas Gadhia]

Hi,I'm trying to use RelBuilder to do a project and join together, however, 
none of the tests in RelBuilderTest.java seem to show an example on how to do 
so.
Is there a place where I can find such an example? I'm trying to dig into Hive 
code to see how its done there, but its taking me quite some time to understand 
the CalcitePlanner.java code in Hive.
Any help would be appreciated.ThanksAbbas