code: def lookup(self, name):
          
  
          if name in self.attributes():
              return getattr(self, IMPL_PREFIX + name)
          raise exceptions.AttributeInferenceError(target=self._instance, attribute=name)
docs: Look up the given *name* in the current model
  
          It should return an AST or an interpreter object,
          but if the name is not found, then an AttributeInferenceError will be raised.