input: 
  def search_sru(sru_instance, query: str, collection: str = None, startrecord: int = 1, maximumrecords: int = 1, recordschema: str = None) -> response:
      """
      Uses a SRU instance to perform a search query and returns a response object containing search results.
      >>> sru_inst = sru()
      >>> result = search_sru(sru_inst, 'digital libraries', 'GGC', 1, 5, 'dcx')
      >>> result.titles
      ['Digital Libraries: Principles and Practice in a Digital World']
      >>> result.identifiersISBN
      ['978-3-319-92583-2']
      """
      return sru_instance.search(query, collection, startrecord, maximumrecords, recordschema)
  
output:     response = sru_instance.search(query, collection, startrecord, maximumrecords, recordschema)
      return response