def test_iam_authenticator():
    authenticator = IAMAuthenticator('my_apikey')
    assert authenticator is not None
    assert authenticator.token_manager.url == 'https://iam.cloud.ibm.com/identity/token'
    assert authenticator.token_manager.client_id is None
    assert authenticator.token_manager.client_secret is None
    assert authenticator.token_manager.disable_ssl_verification is False
    assert authenticator.token_manager.headers is None
    assert authenticator.token_manager.proxies is None
    assert authenticator.token_manager.apikey == 'my_apikey'

    authenticator.set_client_id_and_secret('tom', 'jerry')
    assert authenticator.token_manager.client_id == 'tom'
    assert authenticator.token_manager.client_secret == 'jerry'

    with pytest.raises(TypeError) as err:
        authenticator.set_headers('dummy')
    assert str(err.value) == 'headers must be a dictionary'

    authenticator.set_headers({'dummy': 'headers'})
    assert authenticator.token_manager.headers == {'dummy': 'headers'}

    with pytest.raises(TypeError) as err:
        authenticator.set_proxies('dummy')
    assert str(err.value) == 'proxies must be a dictionary'

    authenticator.set_proxies({'dummy': 'proxies'})
    assert authenticator.token_manager.proxies == {'dummy': 'proxies'}