def read(self):
        """
        Read in all unread lines and return them as a single string.
        """
        lines = self.readlines()
        if lines:
            try:
                return ''.join(lines)
            except TypeError:
                return ''.join(force_text(line) for line in lines)
        else:
            return None
Read in all unread lines and return them as a single string.