class_docstr: Algebatic data type(ADT) object.
  
  Parameters
  ----------
  tag : int
      The tag of ADT.
  
  fields : list[Object] or tuple[Object]
      The source tuple.
code: def __getitem__(self, idx):
      return getitem_helper(self, _ffi_api.GetADTFields, len(self), idx)
  
imports: import tvm._ffi
  from .object import Object, PyNativeObject
  from .object_generic import ObjectTypes
  from .None import _ffi_api
label_desc: Use image node_id 3 for calling the ADT obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: getitem_helper