code: def load(self):
      if self.data is None:
          assert self.loader_fn is not None
          self.data = self.loader_fn()
          self.loader_fn = None
      return self.data
  
imports: from copy import deepcopy
  import aimrocks.lib_rocksdb
label_desc: Use image node_id 4 for calling the BLOB obj's underlying member method code with example usage: obj.load() and returns: self