code: def input_shape(self):
      return (4, 8)
  
imports: import gc
  import inspect
  import unittest
  import torch
  from parameterized import parameterized
  from diffusers import PriorTransformer
  from diffusers.utils.testing_utils import backend_empty_cache, enable_full_determinism, floats_tensor, slow, torch_all_close, torch_device
  from .test_modeling_common import ModelTesterMixin
label_desc: Use image node_id 3 for calling the PriorTransformerTests obj's underlying member method code with example usage: obj.input_shape() and returns: int,  int