code: def test_sanity():
      N = 1000
      constant = LRScheduler(
          "constant", base_lr=0, target_lr=1, niters=N
      )
      linear = LRScheduler("linear", base_lr=1, target_lr=2, niters=N)
      cosine = LRScheduler("cosine", base_lr=3, target_lr=1, niters=N)
      poly = LRScheduler(
          "poly", base_lr=1, target_lr=0, niters=N, power=2
      )
      step = LRScheduler(
          "step",
          base_lr=1,
          target_lr=0,
          niters=N,
          step_iter=[100, 500],
          step_factor=0.1,
      )
  
      compare(constant, 0, 0)
      compare(constant, N - 1, 0)
      compare(linear, 0, 1)
      compare(linear, N - 1, 2)
      compare(cosine, 0, 3)
      compare(cosine, N - 1, 1)
      compare(poly, 0, 1)
      compare(poly, N - 1, 0)
      compare(step, 0, 1)
      compare(step, 100, 0.1)
      compare(step, 500, 0.01)
      compare(step, N - 1, 0.01)
  
file_path: gluon-cv/tests/unittests/test_lr_scheduler.py
imports: from __future__ import print_function
  from __future__ import division
  import os.path
  import mxnet
  import numpy
  import gluoncv
  from mxnet import autograd, gluon
  from math import pi, cos
  from gluoncv.utils import LRScheduler, LRSequential
label_desc: Use image node_id 2 for calling a global function with example usage: test_sanity() without return types