code: def __len__(self):
      return sum(
          1 if isinstance(value, self.value_type) else len(value)
          for value in super().values()
      )
  
imports: from collections import OrderedDict
  from tensorforce import TensorforceError
label_desc: Use image node_id 9 for calling the NestedDict obj's underlying member method code with example usage: obj.__len__() and returns: sum