input: Write a function to create an instance of the "sru" class and search for a query using its "search" method, returning the titles of the search results. If no titles are found, return an empty list. If the search method returns False, also return an empty list. The function should take a query string, a collection name, a start record number, a maximum number of records to return, and a record schema as arguments.
  
  def search_titles(query, collection, startrecord=1, maximumrecords=1, recordschema=False):
      sru_instance = sru()
      search_response = sru_instance.search(query, collection, startrecord, maximumrecords, recordschema)
      if search_response:
          return search_response.titles
      return []
  
  assert search_titles("Dutch", "DPO")==['Early Dutch Books Online']
  assert search_titles("Manuscript", "BYVANCK")==['Medieval Illuminated Manuscripts']
  assert search_titles("UnknownQuery", "DPO")==[]
  assert search_titles("French", "DPO", maximumrecords=0)==[]
output: def search_titles(query, collection, startrecord=1, maximumrecords=1, recordschema=False):
      sru_instance = sru()
      search_response = sru_instance.search(query, collection, startrecord, maximumrecords, recordschema)
      if search_response:
          return search_response.titles
      return []