Present the user with a list of choices.
    return the choice that he selects.
    return None if he cancels the selection selection.

    :ref:`screenshots<choice>`

    :param choices: a list of the choices to be displayed
    :param message: message to be displayed.
    :param title: window title
    :param default: default string of choice
    :rtype: None or string

def choice(choices=[], message='Pick something.', default=None, title=''):
    """
    Present the user with a list of choices.
    return the choice that he selects.
    return None if he cancels the selection selection.

    :ref:`screenshots<choice>`

    :param choices: a list of the choices to be displayed
    :param message: message to be displayed.
    :param title: window title
    :param default: default string of choice
    :rtype: None or string
    """
    return backend_api.opendialog("choice", dict(choices=choices, message=message, default=default, title=title))