run the example.

def example(host, user, password, token):
    """run the example."""
    client = None
    try:
        if token:
            print('token login')
            client = MatrixClient(host, token=token, user_id=user)
        else:
            print('password login')
            client = MatrixClient(host)
            token = client.login_with_password(user, password)
            print('got token: %s' % token)
    except MatrixRequestError as e:
        print(e)
        if e.code == 403:
            print("Bad username or password")
            exit(2)
        elif e.code == 401:
            print("Bad username or token")
            exit(3)
        else:
            print("Verify server details.")
            exit(4)
    except MissingSchema as e:
        print(e)
        print("Bad formatting of URL.")
        exit(5)
    except InvalidSchema as e:
        print(e)
        print("Invalid URL schema")
        exit(6)
    print("is in rooms")
    for room_id, room in client.get_rooms().items():
        print(room_id)