code: def test_sum_image(self):
      t1 = Tensor.ones(16, 16, 1).reshape(16, 4, 4) + 3
      t1.realize()
      t1 = t1.sum()
      t1.realize()
      assert t1.numpy() == 16 * 4 * 4 * 4, f"got {t1.numpy()}"
  
file_path: tinygrad/test/external/external_test_image.py
imports: import os
  import unittest
  import numpy
  from tinygrad.tensor import Tensor
  from tinygrad.nn import Conv2d
label_desc: Use image node_id 2 for calling the TestImage obj's underlying member method code with example usage: obj.test_sum_image() without return types