input: Write a function to implement a Python API for KB SRU. The function should create an instance of the "sru" class and call its "search" method with a query string and optionally a collection name, start record number, maximum number of records to return, and record schema. The method should return a "response" object containing the search results, from which specific information like titles, creators, and subjects can be extracted using the various properties of the "response" object.
  
  
  def kb_sru_search(query, collection=False, startrecord=1, maximumrecords=1, recordschema=False):
      sru_instance = sru()
      response_obj = sru_instance.search(query, collection=collection, startrecord=startrecord, maximumrecords=maximumrecords, recordschema=recordschema)
      if response_obj:
          return response_obj
      return False
  
  # Example assertions to test the function
  assert kb_sru_search('example query', 'GGC').titles != []
  assert kb_sru_search('example query', 'DPO', recordschema='ddd').creators != []
  assert not kb_sru_search('invalid query', 'UNKNOWN')
  assert kb_sru_search('example query', 'BYVANCK', maximumrecords=10).nr_of_records <= 10
  
output: def kb_sru_search(query, collection=False, startrecord=1, maximumrecords=1, recordschema=False):
      sru_instance = sru()
      response_obj = sru_instance.search(query, collection=collection, startrecord=startrecord, maximumrecords=maximumrecords, recordschema=recordschema)
      if response_obj:
          return response_obj
      return False