code: def forward_expected(self, inputs):
      return (force_array(0.0, self.dtype),)
  
imports: import unittest
  import numpy
  import six
  import chainer
  from chainer import functions
  from chainer import testing
  from chainer.utils import force_array
  from chainer.utils import type_check
label_desc: Use image node_id 4 for calling the TestBinaryAccuracyIgnoreAll obj's underlying member method code with example usage: obj.forward_expected(inputs) and returns: force_array