code: public SDVariable standardize(String name, SDVariable x, int... dimensions) {
          validateNumerical("standardize", x);
          SDVariable result = f().standardize(x, dimensions);
          return updateVariableNameAndReference(result, name);
      }
docs: Standardize input variable along given axis
  <p>
  out = (x - mean) / stdev
  <p>
  with mean and stdev being calculated along the given dimension.
  
  <p>
  For example: given x as a mini batch of the shape [numExamples, exampleLength]:
  <ul>
  <li>use dimension 1 too use the statistics (mean, stdev) for each example</li>
  <li>use dimension 0 if you want to use the statistics for each column across all examples</li>
  <li>use dimensions 0,1 if you want to use the statistics across all columns and examples</li>
  </ul>
  
  @param name Name of the output variable
  @param x    Input variable
  @return Output variable