class_docstr: Mapping that only sees ``TensorVariable`` instances (i.e., activation tensors).
code: def __getitem__(self, key):
      if "out_" + key in self.attributes:
          return self.attributes["out_" + key]
      else:
          return self.attributes[key]
  
imports: from collections.abc import MutableMapping
  from numbers import Integral
  from hls4ml.model.types import NamedType, Source, TensorVariable, WeightVariable
  from hls4ml.utils.string_utils import convert_to_pascal_case
label_desc: Use image node_id 2 for calling the VariableMapping obj's underlying member method code with example usage: obj.__getitem__(key) and returns: self, self