'Mark a single base image as in use.'

def _mark_in_use(self, img_id, base_file):

    LOG.info('image    %(id)s    at    (%(base_file)s):    checking', {'id': img_id, 'base_file': base_file})
    if (base_file in self.unexplained_images):
        self.unexplained_images.remove(base_file)
    self.active_base_files.append(base_file)
    LOG.debug('image    %(id)s    at    (%(base_file)s):    image    is    in    use', {'id': img_id, 'base_file': base_file})
    libvirt_utils.update_mtime(base_file)
