$ini_settings = ''
Run a unit test. The return value is one of:
Full path to the test file to run.
Additional customized settings to pass on the command-line to the PHP instance used for testing. For example, requesting disabling use of php.ini or a testing php.ini can be specified. For a full list of possible settings, type:
$ php -h
throws no exceptions thrown
This function can not be called statically.