code: def test_invalid_configs(self):
      self.create()
      with self.assertRaises(ValueError):
          self.optimizer.loss_scaling(interval=0)
      with self.assertRaises(ValueError):
          self.optimizer.loss_scaling(scale=-1)
  
imports: import pickle
  import unittest
  import numpy
  import six
  import chainer
  from chainer import functions
  from chainer import optimizers
  from chainer import testing
label_desc: Use image node_id 3 for calling the TestOptimizerLossScaling obj's underlying member method code with example usage: obj.test_invalid_configs() without return types