How to use the cookiecutter.prompt.render_variable function in cookiecutter

def test_convert_to_str(mocker, raw_var, rendered_var):
    env = environment.StrictEnvironment()
    from_string = mocker.patch(
        'cookiecutter.prompt.StrictEnvironment.from_string',
        wraps=env.from_string
    )
    context = {'project': 'foobar'}

    result = prompt.render_variable(env, raw_var, context)
    assert result == rendered_var

    # Make sure that non None non str variables are converted beforehand
    if raw_var is not None:
        if not isinstance(raw_var, basestring):
            raw_var = str(raw_var)
        from_string.assert_called_once_with(raw_var)
    else:
        assert not from_string.called

def _prompt_choice_and_subitems(cookiecutter_dict, env, key, options, no_input):
    result = {}
    
    # first, get the selection
    rendered_options = [
        render_variable(env, list(raw.keys())[0], cookiecutter_dict) for raw in options
    ]

    if no_input:
        selected = rendered_options[0]
    
    selected = read_user_choice(key, rendered_options)
    
    selected_item = [list(c.values())[0] for c in options if list(c.keys())[0] == selected][0]

    result[selected] = {}

    # then, fill in the sub values for that item
    for subkey, raw in selected_item.items():
        # We are dealing with a regular variable
        val = render_variable(env, raw, cookiecutter_dict)

def render_obj(env, o, cookiecutter_dict):
    if isinstance(o, list):
        return render_list(env, o, cookiecutter_dict)
    elif isinstance(o, dict):
        return render_dict(env, o, cookiecutter_dict)
    else:
        return render_variable(env, o, cookiecutter_dict)

for key, raw in iteritems(context['cookiecutter']):
        if key.startswith('_'):
            # unlike cookiecutter's prompt_for_config, we render internal variables
            cookiecutter_dict[key] = render_obj(env, raw, cookiecutter_dict)
            continue

        try:
            if isinstance(raw, list):
                # We are dealing with a choice variable
                val = prompt_choice_for_config(
                    cookiecutter_dict, env, key, raw, no_input=True
                )
            else:
                # We are dealing with a regular variable
                val = render_variable(env, raw, cookiecutter_dict)
        except UndefinedError as err:
            msg = "Unable to render variable '{}'".format(key)
            raise UndefinedVariableInTemplate(msg, err, context)

        cookiecutter_dict[key] = val

    return { 'cookiecutter' : cookiecutter_dict }

render_variable(env, list(raw.keys())[0], cookiecutter_dict) for raw in options
    ]

    if no_input:
        selected = rendered_options[0]
    
    selected = read_user_choice(key, rendered_options)
    
    selected_item = [list(c.values())[0] for c in options if list(c.keys())[0] == selected][0]

    result[selected] = {}

    # then, fill in the sub values for that item
    for subkey, raw in selected_item.items():
        # We are dealing with a regular variable
        val = render_variable(env, raw, cookiecutter_dict)

        if not no_input:
            val = read_user_variable(subkey, val)

        result[selected][subkey] = val

    return result

try:
            if isinstance(raw, list):
                if isinstance(raw[0], dict):
                    val = _prompt_choice_and_subitems(
                        cookiecutter_dict, env, key, raw, no_input
                    )
                    cookiecutter_dict[key] = val
                else:
                    # We are dealing with a choice variable
                    val = prompt_choice_for_config(
                        cookiecutter_dict, env, key, raw, no_input
                    )
                    cookiecutter_dict[key] = val
            elif not isinstance(raw, dict):
                # We are dealing with a regular variable
                val = render_variable(env, raw, cookiecutter_dict)

                if not no_input:
                    val = read_user_variable(key, val)

                cookiecutter_dict[key] = val
        except UndefinedError as err:
            msg = "Unable to render variable '{}'".format(key)
            raise UndefinedVariableInTemplate(msg, err, context)

    # Second pass; handle the dictionaries.
    for key, raw in iteritems(context[u'cookiecutter']):

        try:
            if isinstance(raw, dict):
                # We are dealing with a dict variable
                val = render_variable(env, raw, cookiecutter_dict)