[Cse143-announce] Testing Code for Regrades

[Ethan Apter]

If you're interested in a regrade for expand() (question #3 of part 2), 
please try the program ExpandTest.java which I've uploaded to the 
regrade page:

http://www.cs.washington.edu/education/courses/cse143/09su/regrade.html

In order to use ExpandTest, simply fill in the code for the expand 
method at the top of the file (don't forget your private method(s)!).  
Then compile and run it.  ExpandTest throws exceptions when your code 
doesn't produce the expected tree, so make sure to read the messages in 
the exceptions.

By far the most common mistake on this problem was creating an incorrect 
number of new nodes.

-Ethan