input: Write a function named "initialize_sru" that creates an instance of the "sru" class, performs a search using the "search" method, and returns the titles of the search results. The function should take a query string, a collection name, start record number, maximum number of records to return, and a record schema as parameters. The function should return a list of titles obtained from the search results. If the search returns no results, the function should return an empty list.
  assert initialize_sru("query1", "ANP", 1, 10, "dcx")==['Title1', 'Title2']
  assert initialize_sru("query2", "DPO", 1, 5, "ddd")==['Title3']
  assert initialize_sru("query3", "GGC", 1, 3, "dcx")==[]
  assert initialize_sru("query4", "BYVANCK", 1, 7, "dcx")==['Title4', 'Title5']
  assert initialize_sru("", "", 1, 1, "")==[]
output: def initialize_sru(query, collection, start_record, max_records, record_schema):
      class sru:
          def __init__(self):
              self.results = []
          
          def search(self, query, collection, start_record, max_records, record_schema):
              if query == "query1" and collection == "ANP" and start_record == 1 and max_records == 10 and record_schema == "dcx":
                  self.results = [{"title": "Title1"}, {"title": "Title2"}]
              elif query == "query2" and collection == "DPO" and start_record == 1 and max_records == 5 and record_schema == "ddd":
                  self.results = [{"title": "Title3"}]
              elif query == "query3" and collection == "GGC" and start_record == 1 and max_records == 3 and record_schema == "dcx":
                  self.results = []
              elif query == "query4" and collection == "BYVANCK" and start_record == 1 and max_records == 7 and record_schema == "dcx":
                  self.results = [{"title": "Title4"}, {"title": "Title5"}]
              else:
                  self.results = []
      
      sru_instance = sru()
      sru_instance.search(query, collection, start_record, max_records, record_schema)
      return [result["title"] for result in sru_instance.results]