How to use the autopep8.Atom function in autopep8

num_tokens = len(tokens)
    while index < num_tokens:
        tok = Token(*tokens[index])

        assert tok.token_type != token.INDENT
        if tok.token_type == tokenize.NEWLINE:
            # There's only one newline and it's at the end.
            break

        if tok.token_string in '([{':
            (container, index) = _parse_container(tokens, index)
            if not container:
                return None
            parsed_tokens.append(container)
        else:
            parsed_tokens.append(Atom(tok))

        index += 1

    return parsed_tokens

break_after_open_bracket and index == 0 and
                # Prefer to keep empty containers together instead of
                # separating them.
                unicode(item) == self.open_bracket and
                (not next_item or unicode(next_item) != self.close_bracket) and
                (len(self._items) != 3 or not isinstance(next_item, Atom))
            ):
                reflowed_lines.add_line_break(continued_indent)
                break_after_open_bracket = False
            else:
                next_next_item = get_item(self._items, index + 2)
                if (
                    unicode(item) not in ['.', '%', 'in'] and
                    next_item and not isinstance(next_item, Container) and
                    unicode(next_item) != ':' and
                    next_next_item and (not isinstance(next_next_item, Atom) or
                                        unicode(next_item) == 'not') and
                    not reflowed_lines.line_empty() and
                    not reflowed_lines.fits_on_current_line(
                        self._get_extent(index + 1) + 2)
                ):
                    reflowed_lines.add_line_break(continued_indent)

def _parse_container(tokens, index, for_or_if=None):
    """Parse a high-level container, such as a list, tuple, etc."""

    # Store the opening bracket.
    items = [Atom(Token(*tokens[index]))]
    index += 1

    num_tokens = len(tokens)
    while index < num_tokens:
        tok = Token(*tokens[index])

        if tok.token_string in ',)]}':
            # First check if we're at the end of a list comprehension or
            # if-expression. Don't add the ending token as part of the list
            # comprehension or if-expression, because they aren't part of those
            # constructs.
            if for_or_if == 'for':
                return (ListComprehension(items), index - 1)

            elif for_or_if == 'if':
                return (IfExpression(items), index - 1)

while index < num_tokens:
        tok = Token(*tokens[index])

        if tok.token_string in ',)]}':
            # First check if we're at the end of a list comprehension or
            # if-expression. Don't add the ending token as part of the list
            # comprehension or if-expression, because they aren't part of those
            # constructs.
            if for_or_if == 'for':
                return (ListComprehension(items), index - 1)

            elif for_or_if == 'if':
                return (IfExpression(items), index - 1)

            # We've reached the end of a container.
            items.append(Atom(tok))

            # If not, then we are at the end of a container.
            if tok.token_string == ')':
                # The end of a tuple.
                return (Tuple(items), index)

            elif tok.token_string == ']':
                # The end of a list.
                return (List(items), index)

            elif tok.token_string == '}':
                # The end of a dictionary or set.
                return (DictOrSet(items), index)

        elif tok.token_string in '([{':
            # A sub-container is being defined.

elif tok.token_string in '([{':
            # A sub-container is being defined.
            (container, index) = _parse_container(tokens, index)
            items.append(container)

        elif tok.token_string == 'for':
            (container, index) = _parse_container(tokens, index, 'for')
            items.append(container)

        elif tok.token_string == 'if':
            (container, index) = _parse_container(tokens, index, 'if')
            items.append(container)

        else:
            items.append(Atom(tok))

        index += 1

    return (None, None)