old_contents: def request(query, params):
      return params
  
  
  def response(resp):
      return []
  
new_contents: ## Dummy
  # 
  # @results     empty array
  # @stable      yes
  
  
  # do search-request
  def request(query, params):
      return params
  
  
  # get response from search-request
  def response(resp):
      return []
  
subject: add comments to dummy engine