input: Write a function to create an instance of the "sru" class and perform a search using its "search" method, passing 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.
  
  def sru_search(query, collection=False, startrecord=1, maximumrecords=1, recordschema=False):
      sru_instance = sru()
      response_obj = sru_instance.search(query, collection, startrecord, maximumrecords, recordschema)
      return response_obj
  
  assert sru_search("title", collection="BYVANCK", maximumrecords=3).nr_of_records > 0
  assert sru_search("title", collection="GGC", maximumrecords=1).nr_of_records == 1
  assert sru_search("nonexistentterm").nr_of_records == 0
  assert sru_search("date", collection="DPO", startrecord=5, maximumrecords=5).nr_of_records <= 5
  assert sru_search("creator", collection="ANP", recordschema="dcx").nr_of_records >= 0
output: 
  def sru_search(query, collection=False, startrecord=1, maximumrecords=1, recordschema=False):
      sru_instance = sru()
      response_obj = sru_instance.search(query, collection, startrecord, maximumrecords, recordschema)
      return response_obj
  