Returns a list of entries contained within a directory.

def listdir(self, dirname):
        """Returns a list of entries contained within a directory."""
        if not self.isdir(dirname):
            raise errors.NotFoundError(None, None, "Could not find directory")

        entries = os.listdir(compat.as_str_any(dirname))
        entries = [compat.as_str_any(item) for item in entries]
        return entries