code: def _get_item(self):
      item = getattr(self, self._item_prop_name, None)
      if item is None:
          raise ValueError("Item property is empty or missing")
      assert isinstance(item, DataModel)
      return item
  
imports: import abc
  import six
  from jsonschema.exceptions import FormatError, SchemaError, ValidationError
  from .apimodel import ApiModel
  from .datamodel import DataModel
  from .defs import ENV_API_DEFAULT_REQ_METHOD
label_desc: Use image node_id 1 for calling the CompoundRequest obj's underlying member method code with example usage: obj._get_item() and returns: item