input: Write a function to create an instance of the "sru" class and call its "search" method with the query string "python", "GGC" collection, and other default parameters. Return the titles of the search results.
  assert lambda obj: obj.titles() == ['Python for Beginners', 'Advanced Python Programming']
output: def search_sru(query, collection):
      sru_instance = sru()
      results = sru_instance.search(query, collection)
      return results.titles()