graph.xml - graph representation in xml properties file;
probs.xml - probability tables;
SimpleBayesNet.svg - a sample that is used to build graph.xml and probs.xml;
BayesNetLoad.java - contains loader class BayesNetData, and example of how 
to use it: download, print and send different requests to the downloaded data.

So students don't need to write their own loader; they only to implement the required algorithm.