code: def forward(self, argument, device=None, outputs_to_retain=None):
      sign = np.sign(argument)
      np.place(sign, sign == 0, -1)
      return argument, sign
  
imports: import numpy
  import cntk
  from cntk.ops.functions import UserFunction
label_desc: Use image node_id 2 for calling the pySign obj's underlying member method code with example usage: obj.forward(argument, device, outputs_to_retain) and returns: argument,  sign