Information if the given grading means passed.
        Non-graded assignments are always passed.

def grading_means_passed(self):
        '''
        Information if the given grading means passed.
        Non-graded assignments are always passed.
        '''
        if self.assignment.is_graded():
            if self.grading and self.grading.means_passed:
                return True
            else:
                return False
        else:
            return True