code: def check_invalid_option(self, xp):
      x = xp.asarray(self.x)
      t = xp.asarray(self.t)
      w = xp.asarray(self.w)
  
      with pytest.raises(ValueError):
          negative_sampling.negative_sampling(
              x, t, w, make_sampler(xp, 5), 2, reduce="invalid_option"
          )
  
imports: import unittest
  import numpy
  import pytest
  import six
  import chainer
  from chainer.backend import CpuDevice
  from chainer.backends import cuda
  from chainer import functions
  from chainer.functions.loss import negative_sampling
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 2 for calling the TestNegativeSamplingInvalidReductionOption obj's underlying member method code with example usage: obj.check_invalid_option(xp) without return types