def METHOD_NAME(self, file):
    """
    Extract template from a single file.
    New templates will be given an auto-increased ID.
    """
    images = unpack(load_image(file))
    for image in images:
        if self.get_items.appear_on(image):
            self.get_items.extract_template(image, folder=self.template_folder)
        if self.campaign_bonus.appear_on(image):
            self.campaign_bonus.extract_template(image, folder=self.template_folder)