old_contents: from glob import glob
  from os.path import join
  
  from flask import Flask
  from flask_script import Command
  
  
  # noinspection PyAbstractClass,PyMethodOverriding
  class DevServerCommand(Command):
      def __call__(self, app):
          extra_files = _templates_paths_for(app)
          app.run(debug=True, extra_files=extra_files)
  
  
  def _templates_paths_for(app: Flask, templates_matcher: str='*.html'):
      templates_directory = join(app.root_path, app.template_folder)
      templates_glob = join(templates_directory, '**', templates_matcher)
      return glob(templates_glob, recursive=True)
  
new_contents: from glob import glob
  from os.path import join
  
  from flask import Flask
  from flask_script import Command
  
  
  # noinspection PyAbstractClass,PyMethodOverriding
  class DevServerCommand(Command):
      def __call__(self, app: Flask):
          extra_files = _templates_paths_for(app)
          app.run(debug=True, extra_files=extra_files)
  
  
  def _templates_paths_for(app: Flask, templates_matcher: str='*.html'):
      templates_directory = join(app.root_path, app.template_folder)
      templates_glob = join(templates_directory, '**', templates_matcher)
      return glob(templates_glob, recursive=True)
  
subject: Add missing type annotation