input: Write a function to create an instance of the "sru" class and call its "search" method, passing in a query string and optionally a collection name, start record number, maximum number of records to return, and record schema. The function should return a "response" object containing the results of the search. Use the assert function to test the implementation with different inputs.
  
  assert search_kb_sru("books", "GGC", 1, 10, "dcx").nr_of_records > 0
  assert not search_kb_sru("nonexistent", "GGC", 1, 10, "dcx")
  assert search_kb_sru("books", "ANP", 1, 10, "dcx").nr_of_records > 0
  assert not search_kb_sru("nonexistent", "ANP", 1, 10, "dcx")
  assert search_kb_sru("books", startrecord=1, maximumrecords=10).nr_of_records > 0
output: def search_kb_sru(query, collection=None, startrecord=1, maximumrecords=10, recordschema="dcx"):
      sru_instance = sru()
      response = sru_instance.search(query, collection, startrecord, maximumrecords, recordschema)
      return response