code: def get_annotation_types(self, item_url):
          
          req_url = item_url + "/annotations/types"
          resp = self.api_request(req_url)
          return resp['annotation_types']
docs: Retrieve the annotation types for the given item from the server
  
          :type item_url: String or Item
          :param item_url: URL of the item, or an Item object
  
          :rtype: List
          :returns: a List specifying the annotation types
  
          :raises: APIError if the request was not successful