Create a package finder appropriate to this requirement command.

def _build_package_finder(
        self,
        options,               # type: Values
        session,               # type: PipSession
        platform=None,         # type: Optional[str]
        python_versions=None,  # type: Optional[List[str]]
        abi=None,              # type: Optional[str]
        implementation=None    # type: Optional[str]
    ):
        # type: (...) -> PackageFinder
        """
        Create a package finder appropriate to this requirement command.
        """
        index_urls = [options.index_url] + options.extra_index_urls
        if options.no_index:
            logger.debug(
                'Ignoring indexes: %s',
                ','.join(redact_password_from_url(url) for url in index_urls),
            )
            index_urls = []

        return PackageFinder(
            find_links=options.find_links,
            format_control=options.format_control,
            index_urls=index_urls,
            trusted_hosts=options.trusted_hosts,
            allow_all_prereleases=options.pre,
            session=session,
            platform=platform,
            versions=python_versions,
            abi=abi,
            implementation=implementation,
            prefer_binary=options.prefer_binary,
        )