def __init__(
        self,
        url,                   # type: str
        comes_from=None,       # type: Optional[Union[str, HTMLPage]]
        requires_python=None,  # type: Optional[str]
        yanked_reason=None,    # type: Optional[Text]
        cache_link_parsing=True,  # type: bool
    ):
        # type: (...) -> None
        """
        :param url: url of the resource pointed to (href of the link)
        :param comes_from: instance of HTMLPage where the link was found,
            or string.
        :param requires_python: String containing the `Requires-Python`
            metadata field, specified in PEP 345. This may be specified by
            a data-requires-python attribute in the HTML link tag, as
            described in PEP 503.
        :param yanked_reason: the reason the file has been yanked, if the
            file has been yanked, or None if the file hasn't been yanked.
            This is the value of the "data-yanked" attribute, if present, in
            a simple repository HTML link. If the file has been yanked but
            no reason was provided, this should be the empty string. See
            PEP 592 for more information and the specification.
        :param cache_link_parsing: A flag that is used elsewhere to determine
                                   whether resources retrieved from this link
                                   should be cached. PyPI index urls should
                                   generally have this set to False, for
                                   example.
        """

        # url can be a UNC windows share
        if url.startswith('\\\\'):
            url = path_to_url(url)

        self._parsed_url = urllib_parse.urlsplit(url)
        # Store the url as a private attribute to prevent accidentally
        # trying to set a new value.
        self._url = url

        self.comes_from = comes_from
        self.requires_python = requires_python if requires_python else None
        self.yanked_reason = yanked_reason

        super(Link, self).__init__(key=url, defining_class=Link)

        self.cache_link_parsing = cache_link_parsing

        :param url: url of the resource pointed to (href of the link)
        :param comes_from: instance of HTMLPage where the link was found,
            or string.
        :param requires_python: String containing the `Requires-Python`
            metadata field, specified in PEP 345. This may be specified by
            a data-requires-python attribute in the HTML link tag, as
            described in PEP 503.
        :param yanked_reason: the reason the file has been yanked, if the
            file has been yanked, or None if the file hasn't been yanked.
            This is the value of the "data-yanked" attribute, if present, in
            a simple repository HTML link. If the file has been yanked but
            no reason was provided, this should be the empty string. See
            PEP 592 for more information and the specification.
        :param cache_link_parsing: A flag that is used elsewhere to determine
                                   whether resources retrieved from this link
                                   should be cached. PyPI index urls should
                                   generally have this set to False, for
                                   example.
        
product/gradle-plugin/src/main/python/pip/_internal/models/link.py