code: def test_get_lr_scheduler(scheduler_type, expected_instance):
      scheduler_class, scheduler_kwargs = lr_scheduler.get_lr_scheduler(
          scheduler_type=scheduler_type,
          base_learning_rate=1,
          learning_rate_reduce_factor=0.5,
          learning_rate_reduce_num_not_improved=16,
          learning_rate_warmup=1000,
          max_updates=10000,
      )
      if expected_instance is None:
          assert scheduler_class is None
          assert scheduler_kwargs == {}
      else:
          assert scheduler_class is not None
          scheduler = scheduler_class(
              optimizer=torch.optim.Adam(params=[torch.zeros(0)]),
              **scheduler_kwargs,
          )
          assert isinstance(scheduler, expected_instance)
  
imports: import pytest
  import numpy
  import torch
  from sockeye import lr_scheduler
label_desc: Use image node_id 3 for calling a global function with example usage: test_get_lr_scheduler(scheduler_type, expected_instance) without return types