How to use the cget.package.PackageSource function in cget

def parse_src_github(self, name, url):
        p, v = parse_src_name(url, 'HEAD')
        if '/' in p: url = 'https://github.com/{0}/archive/{1}.tar.gz'.format(p, v)
        else: url = 'https://github.com/{0}/{0}/archive/{1}.tar.gz'.format(p, v)
        if name is None: name = p
        return PackageSource(name=name, url=url)

def to_fname(self):
        if isinstance(self.pkg_src, PackageSource): return self.pkg_src.to_fname()
        else: return self.pkg_src

def parse_pkg_src(self, pkg, start=None, no_recipe=False):
        if isinstance(pkg, PackageSource): return pkg
        if isinstance(pkg, PackageBuild): return self.parse_pkg_src(pkg.pkg_src, start)
        name, url = parse_alias(pkg)
        self.log('parse_pkg_src:', name, url, pkg)
        if '://' not in url:
            return self.parse_src_file(name, url, start) or \
                (None if no_recipe else self.parse_src_recipe(name, url)) or \
                self.parse_src_github(name, url)
        return PackageSource(name=name, url=url)

def parse_src_file(self, name, url, start=None):
        f = util.actual_path(url, start)
        self.log('parse_src_file actual_path:', start, f)
        if os.path.exists(f): return PackageSource(name=name, url='file://' + f)
        return None

def parse_pkg_src(self, pkg, start=None, no_recipe=False):
        if isinstance(pkg, PackageSource): return pkg
        if isinstance(pkg, PackageBuild): return self.parse_pkg_src(pkg.pkg_src, start)
        name, url = parse_alias(pkg)
        self.log('parse_pkg_src:', name, url, pkg)
        if '://' not in url:
            return self.parse_src_file(name, url, start) or \
                (None if no_recipe else self.parse_src_recipe(name, url)) or \
                self.parse_src_github(name, url)
        return PackageSource(name=name, url=url)

def fname_to_pkg(fname):
    if fname.startswith('_url_'): return PackageSource(name=decode_url(fname), fname=fname)
    else: return PackageSource(name=fname.replace('__', '/'), fname=fname)