code: def test_step_decay(self):
      sched = objax.optimizer.scheduler.StepDecay(
          step_size=3, base_lr=1, gamma=0.9
      )
      lrs = []
      for i in range(10):
          lrs.append(sched(step=i))
      lrs_gt = [1, 1, 1, 0.9, 0.9, 0.9, 0.81, 0.81, 0.81, 0.729]
      np.testing.assert_array_almost_equal(lrs, lrs_gt)
  
file_path: objax/tests/scheduler.py
imports: import unittest
  import numpy
  import objax
label_desc: Use image node_id 2 for calling the TestScheduler obj's underlying member method code with example usage: obj.test_step_decay() without return types