def METHOD_NAME(basic_auth_str):
    try:
        creds_b64 = basic_auth_str.split(' ')[1]
        creds_str = b64decode(creds_b64).decode()
        user, password = creds_str.split(':')
        return user, password
    except Exception:
        raise ValueError("Wrong 'Authorization' header format: %s" % (basic_auth_str,))