code: def test_end2end_cosine(self):
      self._run_end2end(lr_scheduler="cosine", warmup_updates=0)
      self._run_end2end(lr_scheduler="cosine", warmup_updates=50)
  
imports: import os
  import unittest
  import torch
  import parlai.nn.lr_scheduler
  import parlai.utils.testing
label_desc: Use image node_id 10 for calling the TestLRSchedulers obj's underlying member method code with example usage: obj.test_end2end_cosine() without return types