A small example of an implementation of a small domain model. The example
consists of two files. The first file Invites contains the implementation of
the domain model. The second file InvitesTest contains a PHPUnit test suite
to test the domain.
The two files contain comments about what is happening.
The PHPUnit tests can be run by changing to the directory of the tests and running:
$ phpunit .
PHPUnit 4.1.0 by Sebastian Bergmann.
.......
Time: 70 ms, Memory: 4.00Mb
OK (7 tests, 9 assertions)