'If --testmodule is specified twice, once for module A and once for
a module which refers to module A, then make sure module A is only
added once.'

def test_testmoduleOnSourceAndTarget(self):

    self.config.opt_testmodule(sibpath('moduletest.py'))
    self.config.opt_testmodule(sibpath('test_log.py'))
    self.assertSuitesEqual(trial._getSuite(self.config), ['twisted.trial.test.test_log'])
