code: public SDVariable pad(String outputName, SDVariable input, SDVariable padding, Pad.Mode mode, double constant){
          SDVariable out = f().pad(input, padding, mode, constant);
          return updateVariableNameAndReference(out, outputName);
      }
docs: As per {@link #pad(SDVariable, SDVariable, double)} but also supports multiple {@link Pad.Mode} modes.<br>
  Example:
  Input array:<br>
  [1, 2]<br>
  [3, 4]<br>
  [5, 6]<br>
  Padding array:<br>
  [2, 0]<br>
  [1, 1]<br>
  Contant = 0<br>
  Result: CONSTANT mode<br>
  [0, 0, 0, 0]<br>
  [0, 0, 0, 0]<br>
  [0, 1, 2, 0]<br>
  [0, 3, 4, 0]<br>
  [0, 5, 6, 0]<br>
  <br>
  Result: SYMMETRIC mode<br>
  [3, 3, 4, 4]<br>
  [1, 1, 2, 2]<br>
  [1, 1, 2, 2]<br>
  [3, 3, 4, 4]<br>
  [5, 5, 6, 6]<br>
  <br>
  Result: REFLECT:<br>
  [6, 5, 6, 0]<br>
  [2, 3, 4, 3]<br>
  [2, 1, 2, 1]<br>
  [4, 3, 4, 3]<br>
  [6, 5, 6, 5]<br>
  <br>
  @param outputName
  @param input
  @param padding
  @param mode
  @param constant
  @return