The median method returns the median of its three input numbers.  It
is based on the "mid" program in Dr. James A. Jones' Ph.D.
dissertation from Georgia Institue of Technology published in 2008.

This particular program version is annotated with new assertions that
check correctness of the median algorithm.  These assertions can
simply be used as runtime checks for test executions as demonstrated
by the three given tests or be utilized in the evaluation of
assertion-driven techniques, e.g., as in Yang et al.'s ICSE 2014 paper
on iProperty.

To execute the program simply invoke JUnit to run the example test
cases or directly invoke the median method from another Java method.
