How to use the soupsieve.css_parser._Selector function in soupsieve

print('    is_not: True')
            if is_html:
                print('    is_html: True')
            if is_default:
                print('    is_default: True')
            if is_indeterminate:
                print('    is_indeterminate: True')
            if is_in_range:
                print('    is_in_range: True')
            if is_out_of_range:
                print('    is_out_of_range: True')
            if is_placeholder_shown:
                print('    is_placeholder_shown: True')

        if is_relative:
            selectors.append(_Selector())

        try:
            while True:
                key, m = next(iselector)

                # Handle parts
                if key == "at_rule":
                    raise NotImplementedError("At-rules found at position {}".format(m.start(0)))
                elif key == 'pseudo_class_custom':
                    has_selector = self.parse_pseudo_class_custom(sel, m, has_selector)
                elif key == 'pseudo_class':
                    has_selector, is_html = self.parse_pseudo_class(sel, m, has_selector, iselector, is_html)
                elif key == 'pseudo_element':
                    raise NotImplementedError("Pseudo-element found at position {}".format(m.start(0)))
                elif key == 'pseudo_contains':
                    has_selector = self.parse_pseudo_contains(sel, m, has_selector)

def parse_selectors(self, iselector, index=0, flags=0):
        """Parse selectors."""

        sel = _Selector()
        selectors = []
        has_selector = False
        closed = False
        relations = []
        rel_type = ":" + WS_COMBINATOR
        is_open = bool(flags & FLG_OPEN)
        is_pseudo = bool(flags & FLG_PSEUDO)
        is_relative = bool(flags & FLG_RELATIVE)
        is_not = bool(flags & FLG_NOT)
        is_html = bool(flags & FLG_HTML)
        is_default = bool(flags & FLG_DEFAULT)
        is_indeterminate = bool(flags & FLG_INDETERMINATE)
        is_in_range = bool(flags & FLG_IN_RANGE)
        is_out_of_range = bool(flags & FLG_OUT_OF_RANGE)
        is_placeholder_shown = bool(flags & FLG_PLACEHOLDER_SHOWN)

# Value starts with word in dash separated list
            pattern = re.compile(r'^%s(?:-.*)?$' % re.escape(value), flags)
        else:
            # Value matches
            pattern = re.compile(r'^%s$' % re.escape(value), flags)
            if op.startswith('!'):
                # Equivalent to `:not([attr=value])`
                inverse = True
        if is_type and pattern:
            pattern2 = re.compile(pattern.pattern)

        # Append the attribute selector
        sel_attr = ct.SelectorAttribute(attr, ns, pattern, pattern2)
        if inverse:
            # If we are using `!=`, we need to nest the pattern under a `:not()`.
            sub_sel = _Selector()
            sub_sel.attributes.append(sel_attr)
            not_list = ct.SelectorList([sub_sel.freeze()], True, False)
            sel.selectors.append(not_list)
        else:
            sel.attributes.append(sel_attr)

        has_selector = True
        return has_selector

sel.rel_type = rel_type
                selectors[-1].relations.append(sel)
            elif rel_type[1:] != WS_COMBINATOR:
                # It's impossible to have two whitespace combinators after each other as the patterns
                # will gobble up trailing whitespace. It is also impossible to have a whitespace
                # combinator after any other kind for the same reason. But we could have
                # multiple non-whitespace combinators. So if the current combinator is not a whitespace,
                # then we've hit the multiple combinator case, so we should fail.
                raise SelectorSyntaxError(
                    'The multiple combinators at position {}'.format(index),
                    self.pattern,
                    index
                )
            # Set the leading combinator for the next selector.
            rel_type = ':' + combinator
        sel = _Selector()

        has_selector = False
        return has_selector, sel, rel_type

index
            )

        if combinator == COMMA_COMBINATOR:
            if not sel.tag and not is_pseudo:
                # Implied `*`
                sel.tag = ct.SelectorTag('*', None)
            sel.relations.extend(relations)
            selectors.append(sel)
            del relations[:]
        else:
            sel.relations.extend(relations)
            sel.rel_type = combinator
            del relations[:]
            relations.append(sel)
        sel = _Selector()

        has_selector = False
        return has_selector, sel

combinator = m.group('relation').strip()
        if not combinator:
            combinator = WS_COMBINATOR
        if combinator == COMMA_COMBINATOR:
            if not has_selector:
                # If we've not captured any selector parts, the comma is either at the beginning of the pattern
                # or following another comma, both of which are unexpected. Commas must split selectors.
                raise SelectorSyntaxError(
                    "The combinator '{}' at postion {}, must have a selector before it".format(combinator, index),
                    self.pattern,
                    index
                )
            sel.rel_type = rel_type
            selectors[-1].relations.append(sel)
            rel_type = ":" + WS_COMBINATOR
            selectors.append(_Selector())
        else:
            if has_selector:
                # End the current selector and associate the leading combinator with this selector.
                sel.rel_type = rel_type
                selectors[-1].relations.append(sel)
            elif rel_type[1:] != WS_COMBINATOR:
                # It's impossible to have two whitespace combinators after each other as the patterns
                # will gobble up trailing whitespace. It is also impossible to have a whitespace
                # combinator after any other kind for the same reason. But we could have
                # multiple non-whitespace combinators. So if the current combinator is not a whitespace,
                # then we've hit the multiple combinator case, so we should fail.
                raise SelectorSyntaxError(
                    'The multiple combinators at position {}'.format(index),
                    self.pattern,
                    index
                )