code: def copy_binder_files(app, exception):
      
      if exception is not None:
          return
  
      if app.builder.name not in ['html', 'readthedocs']:
          return
  
      gallery_conf = app.config.sphinx_gallery_conf
      binder_conf = check_binder_conf(gallery_conf.get('binder'))
  
      if not len(binder_conf) > 0:
          return
  
      logger.info('copying binder requirements...', color='white')
      _copy_binder_reqs(app, binder_conf)
      _copy_binder_notebooks(app)
docs: Copy all Binder requirements and notebooks files.