code: def forward_xp(self, inputs, xp):
      (x,) = inputs
      axis = self.axis
      if xp is chainerx:
          return (chainerx.log_softmax(x, axis=axis),)
      x = x.astype(self.out_dtype)
      axis = axis if axis is not None else 1
      return (
          x - numpy.log(numpy.exp(x).sum(axis=axis, keepdims=True)),
      )
  
imports: import chainer
  import numpy
  import pytest
  import chainerx
  import chainerx.testing
  from chainerx_tests import array_utils
  from chainerx_tests import math_utils
  from chainerx_tests import op_utils
label_desc: Use image node_id 2 for calling the TestLogSoftmax obj's underlying member method code with example usage: obj.forward_xp(inputs, xp) and returns: unknown, chainerx