Pre-/post-processing video macro
Unit-testing utilities are provided by testing package. To create a
unit-test make a php script file unit_tests.php in the 'include' directory of the testing package. Then create a class 'unit_tests' in this file.
All methods wich are started with 'test_' prefix are considered to be unit-tests and will be called. There are also two
specific functions 'set_up' and 'tear_down' wich can be used to create and delete data for testing. Each unit-test must return 'TEST PASSED' string
if a test was passed successfully (more information can be found here: section 'HTTP gateway').