code: def in_dir(config_dir=CONFIG_DIR, extensions=['.yml', '.yaml', '.json']):
      
      configs = []
  
      for filename in os.listdir(config_dir):
          if is_config_file(filename, extensions) and not filename.startswith('.'):
              configs.append(filename)
  
      return configs
docs: Return a list of configs in ``config_dir``.
  
      :param config_dir: directory to search
      :type config_dir: str
      :param extensions: filetypes to check (e.g. ``['.yaml', '.json']``).
      :type extensions: list
      :rtype: list