code: def func(self, xp, a):
      if xp is numpy:
          return numpy.asarray(
              numpy.reciprocal(1 + numpy.exp(-a))
          ).astype(a.dtype)
      return xp.sigmoid(a)
  
imports: import random
  import chainer
  import numpy
  import chainerx
  from chainer import utils
  from chainerx_tests import array_utils
  from chainerx_tests import dtype_utils
  from chainerx_tests import op_utils
label_desc: Use image node_id 1 for calling the TestSigmoid obj's underlying member method code with example usage: obj.func(xp, a) and returns: xp, numpy