code: def test_lamb(self):
      self._test_lamb(1, {"lr": 0.001}, 1e-5, 0)
  
imports: import unittest
  import numpy
  import tensorflow
  import tensorflow_addons
  from tinygrad.tensor import Tensor
  from tinygrad.nn.optim import LAMB
label_desc: Use image node_id 3 for calling the ExternalTestOptim obj's underlying member method code with example usage: obj.test_lamb() without return types