def get_revision(cls, location):
        """
        Return the maximum revision for all files under a given location
        """
        # Note: taken from setuptools.command.egg_info
        revision = 0

        for base, dirs, files in os.walk(location):
            if cls.dirname not in dirs:
                dirs[:] = []
                continue    # no sense walking uncontrolled subdirs
            dirs.remove(cls.dirname)
            entries_fn = os.path.join(base, cls.dirname, 'entries')
            if not os.path.exists(entries_fn):
                # FIXME: should we warn?
                continue

            dirurl, localrev = cls._get_svn_url_rev(base)

            if base == location:
                base = dirurl + '/'   # save the root url
            elif not dirurl or not dirurl.startswith(base):
                dirs[:] = []
                continue    # not part of the same svn tree, skip it
            revision = max(revision, localrev)
        return revision

        Return the maximum revision for all files under a given location
        
product/gradle-plugin/src/main/python/pip/_internal/vcs/subversion.py