Contains all of the standard Test::Unit assertions. Mixed in to Test::Unit::TestCase. To mix it in and use its
functionality, you simply need to rescue Test::Unit::AssertionFailedError, and
you can additionally override add_assertion to be notified whenever an
assertion is made.
Notes:
The message to each assertion, if given, will be propagated with the
failure.
It's easy to add your own assertions based on assert_block().
Passes if expected == actual. Note that the ordering of arguments is
important, since a helpful error message is generated when this one fails
that tells you the values of expected and actual.