How to use the setupmeta.readlines function in setupmeta

def load_contents(relative_path, limit=0):
    """Return contents of file with 'relative_path'

    :param str relative_path: Relative path to file
    :param int limit: Max number of lines to load
    :return str|None: Contents, if any
    """
    lines = setupmeta.readlines(relative_path, limit=limit)
    if lines is not None:
        return "".join(lines).strip()

def __init__(self, root):
        self.path = os.path.join(root, "PKG-INFO")
        self.info = {}
        self.name = None
        self.dependency_links = None
        self.entry_points_txt = None
        self.requires_txt = None
        lines = readlines(self.path)
        if not lines:
            return

        # Parse PKG-INFO when present
        key = None
        for line_number, line in enumerate(lines, start=1):
            m = RE_PKG_KEY_VALUE.match(line)
            if m:
                key = m.group(1).lower().replace("-", "_")
                key = self._canonical_names.get(key, key)
                if key not in MetaDefs.all_fields:
                    continue

                value = m.group(2)
                if key in self._list_types:
                    if key not in self.info:

def load_readme(relative_path, limit=0):
    """ Loader for README files """
    lines = setupmeta.readlines(relative_path, limit=limit)
    if lines is not None:
        content = []
        for line in lines:
            m = RE_README_TOKEN.search(line)
            if not m:
                content.append(line)
                continue

            pre, post = m.group(1), m.group(4)
            pre = pre and pre.strip()
            post = post and post.strip()
            if pre or post:
                content.append(line)
                continue  # Not beginning/end, or no spaces around

            action = m.group(2)