code: def __verify_category_exists(self, category):
      if not self.get_category(category):
          raise ValueError(
              "Category "
              + category
              + " does not exist for version "
              + self.api_version
              + "."
          )
  
imports: import json
  import os
  from requests.auth import HTTPBasicAuth
  import requests
label_desc: Use image node_id 16 for calling the ReadMeSession obj's underlying member method code with example usage: obj.__verify_category_exists(category) without return types