code: def _generate_filenames(pattern, channel, segments):
      """Generate the filenames for *channel* and *segments*."""
      if channel in ["PRO", "EPI"]:
          new_files = [pattern.format(channel="", segment=channel)]
      else:
          new_files = (
              pattern.format(channel=channel, segment=f"{segment:06d}")
              for segment in segments
          )
      return new_files
  
file_path: satpy/satpy/demo/seviri_hrit.py
imports: import logging
  import os.path
  from satpy import config
  from satpy.demo.utils import download_url
label_desc: Use image node_id 3 for calling a global function with example usage: _generate_filenames(pattern, channel, segments) and returns: new_files