old_contents: from cla_public.apps.base import base
  
  @base.app_template_filter()
  def test(value):
      return value
  
new_contents: import re
  from cla_public.apps.base import base
  
  @base.app_template_filter()
  def matches(value, pattern):
      return bool(re.search(pattern, value))
  
subject: Update custom template filter