UnitTester::assertFalse PHP Method

    public function assertFalse($condition, $message = null)
    {
        return $this->scenario->runStep(new \Codeception\Step\Action('assertFalse', func_get_args()));
    }

 public function testWrongTimestamps()
 {
     foreach ($this->bad_timestamps as $bad) {
         $this->modelWValidation->start_date = $bad;
         $this->tester->assertFalse($this->modelWValidation->save());
     }
 }