code: def __call__(self, x):
      if self.b is not None:
          return chx.conv(
              x, self.W, self.b, stride=self.stride, pad=self.pad
          )
      else:
          return chx.conv(x, self.W, stride=self.stride, pad=self.pad)
  
imports: import numpy
  import chainerx
label_desc: Use image node_id 3 for calling the Convolution2D obj's underlying member method code with example usage: obj.__call__(x) and returns: chx, chx