def is_utf8_encoded(bstring):
    """
    Return ``True`` if the given byte string can be decoded
    into a Unicode string using the UTF-8 decoder.

    :param bytes bstring: the string to test
    :rtype: bool
    """
    try:
        bstring.decode('utf-8')
        return True
    except UnicodeDecodeError:
        pass
    return False
