code: def test_invsqrt_resume(self):
      self._run_resume(
          lr_scheduler="invsqrt", warmup_updates=0, end_zero=True
      )
      self._run_resume(
          lr_scheduler="invsqrt", warmup_updates=50, end_zero=True
      )
  
imports: import os
  import unittest
  import torch
  import parlai.nn.lr_scheduler
  import parlai.utils.testing
label_desc: Use image node_id 8 for calling the TestLRSchedulers obj's underlying member method code with example usage: obj.test_invsqrt_resume() without return types