code: def check_invalid_option(self, xp):
      x = xp.asarray(self.x)
      t = xp.asarray(self.t)
      with self.assertRaises(ValueError):
          functions.huber_loss(x, t, 1, "invalid_option")
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
  from chainer import utils
label_desc: Use image node_id 2 for calling the TestHuberLossInvalidReductionOption obj's underlying member method code with example usage: obj.check_invalid_option(xp) without return types