def _get_iam_rest_api_url_from_creds(rest_client, credentials):
res = rest_client.make_request(credentials[_IAMConstants.V2_REST_URL])<EOL>base = res['<STR_LIT>']<EOL>end = base.find('<STR_LIT>')<EOL>return base[:end] + '<STR_LIT>'<EOL>
Retrieves the Streams REST API URL from the provided credentials using iam authentication.
    Args:
        rest_client (:py:class:`rest_primitives._IAMStreamsRestClient`): A client  for making REST calls using IAM authentication
        credentials (dict): A dict representation of the credentials.
    Returns:
        str: The remote Streams REST API URL.