def list_should_not_contain_duplicates(self, list_, msg=None):
        if not isinstance(list_, list):
            list_ = list(list_)
        dupes = []
        for item in list_:
            if item not in dupes:
                count = list_.count(item)
                if count > 1:
                    print "*INFO* '%s' found %d times" % (item, count)
                    dupes.append(item)
        if dupes:
            if not msg:
                msg = '%s found multiple times' % seq2str(dupes)
            raise AssertionError(msg)
Fails if any element in the `list` is found from it more than once.
dataset/ETHPy150Open shellderp/sublime-robot-plugin/lib/robot/libraries/Collections.py/_List.list_should_not_contain_duplicates