code: def prepareSystem(cls):
          
          try:
              resourceRootDirPath = os.environ[cls.rootDirPathEnvName]
          except KeyError:
              # Create directory holding local copies of requested resources ...
              resourceRootDirPath = mkdtemp()
              # .. and register its location in an environment variable such that child processes
              # can find it.
              os.environ[cls.rootDirPathEnvName] = resourceRootDirPath
          assert os.path.isdir(resourceRootDirPath)
docs: Prepares this system for the downloading and lookup of resources. This method should only
          be invoked on a worker node. It is idempotent but not thread-safe.