code: public SDVariable selu(String name, SDVariable x) {
          validateFloatingPoint("selu", x);
          SDVariable ret = f().selu(x);
          return updateVariableNameAndReference(ret, name);
      }
docs: Element-wise SeLU function - Scaled exponential Lineal Unit: see <a href="https://arxiv.org/abs/1706.02515">Self-Normalizing Neural Networks</a>
  <br>
  out[i] = scale * alpha * (exp(in[i])-1) if in[i]>0, or 0 if in[i] <= 0<br>
  Uses default lcale and alpha values.
  
  @param name Name of the output variable
  @param x    Input variable
  @return Output variable