class_docstr: Predefined distribution class for n-class classification problems.
code: def gamma(self, w, y, z, f):
      import java.lang.Math as math
  
      absz = math.abs(z)
      return [w * z, w * (absz * (1 - absz))]
  
label_desc: Use image node_id 4 for calling the CustomDistributionMultinomial obj's underlying member method code with example usage: obj.gamma(w, y, z, f) and returns: list