How to use the tern.command_lib.command_lib.get_base_listing function in tern

def get_shell(image_obj, binary):
    # set up a notice origin referring to the base command library listing
    origin_command_lib = formats.invoking_base_commands
    # find the shell to invoke commands in
    shell, _ = command_lib.get_image_shell(
        command_lib.get_base_listing(binary))
    if not shell:
        # add a warning notice for no shell in the command library
        logger.warning('No shell listing in command library. '
                       'Using default shell')
        no_shell_message = errors.no_shell_listing.format(
            binary=binary, default_shell=constants.shell)
        image_obj.layers[0].origins.add_notice_to_origins(
            origin_command_lib, Notice(no_shell_message, 'warning'))
        # add a hint notice to add the shell to the command library
        add_shell_message = errors.no_listing_for_base_key.format(
            listing_key='shell')
        image_obj.layers[0].origins.add_notice_to_origins(
            origin_command_lib, Notice(add_shell_message, 'hint'))
        shell = constants.shell

    return shell

def print_base_invoke(key):
    '''Given the key in the base library, return a string containing
    the command_lib/base.yml'''
    info = command_lib.get_base_listing(key)
    report = ''
    for item in command_lib.base_keys:
        if item in info.keys():
            report = report + print_invoke_list(info, item)
    report = report + '\n'
    return report

dhelper.set_imported_layers(image_obj)
    # add notices for each layer if it is imported
    image_setup(image_obj)
    shell = ''
    # set up empty master list of packages
    master_list = []
    # find the binary by mounting the base layer
    target = rootfs.mount_base_layer(image_obj.layers[0].tar_file)
    binary = common.get_base_bin()
    # set up a notice origin referring to the base command library listing
    origin_command_lib = formats.invoking_base_commands
    # set up a notice origin for the first layer
    origin_first_layer = 'Layer: ' + image_obj.layers[0].fs_hash[:10]
    # find the shell to invoke commands in
    shell, _ = command_lib.get_image_shell(
        command_lib.get_base_listing(binary))
    if not shell:
        # add a warning notice for no shell in the command library
        logger.warning('No shell listing in command library. '
                       'Using default shell')
        no_shell_message = errors.no_shell_listing.format(
            binary=binary, default_shell=constants.shell)
        image_obj.layers[0].origins.add_notice_to_origins(
            origin_command_lib, Notice(no_shell_message, 'warning'))
        # add a hint notice to add the shell to the command library
        add_shell_message = errors.no_listing_for_base_key.format(
            listing_key='shell')
        image_obj.layers[0].origins.add_notice_to_origins(
            origin_command_lib, Notice(add_shell_message, 'hint'))
        shell = constants.shell
    # only extract packages if there is a known binary and the layer is not
    # cached

def add_base_packages(image_layer, binary, shell):
    '''Given the image layer, the binary to invoke and shell:
        1. get the listing from the base.yml
        2. Invoke any commands against the base layer
        3. Make a list of packages and add them to the layer'''
    origin_layer = 'Layer: ' + image_layer.fs_hash[:10]
    if image_layer.created_by:
        image_layer.origins.add_notice_to_origins(origin_layer, Notice(
            formats.layer_created_by.format(created_by=image_layer.created_by),
            'info'))
    else:
        image_layer.origins.add_notice_to_origins(origin_layer, Notice(
            formats.no_created_by, 'warning'))
    origin_command_lib = formats.invoking_base_commands
    # find the binary
    listing = command_lib.get_base_listing(binary)
    if listing:
        # put info notice about what is going to be invoked
        snippet_msg = formats.invoke_for_base + '\n' + \
            content.print_base_invoke(binary)
        image_layer.origins.add_notice_to_origins(
            origin_layer, Notice(snippet_msg, 'info'))
        shell, _ = command_lib.get_image_shell(listing)
        if not shell:
            shell = constants.shell
        # get all the packages in the base layer
        pkg_dict, invoke_msg, warnings = collate_list_metadata(shell, listing)
        if invoke_msg:
            image_layer.origins.add_notice_to_origins(
                origin_layer, Notice(invoke_msg, 'error'))
        if warnings:
            image_layer.origins.add_notice_to_origins(