def contains_at(self, x, index):
        """Tests if given [list of] string is at given index."""

        try:
            if is_collection(x):
                for _x in x:
                    if (_x in self.all[index]) or (_x == self.all[index]):
                        return True
                    else:
                        return False
            else:
                return (x in self.all[index])

        except IndexError:
            return False
Tests if given [list of] string is at given index.