code: @Override
      public synchronized String execute(SampleResult previousResult, Sampler currentSampler)
              throws InvalidVariableException {
          JMeterVariables vars = getVariables();
          String res = ((CompoundVariable) values[0]).execute().toUpperCase();
  
          if (vars != null && values.length > 1) {
              String varName = ((CompoundVariable) values[1]).execute().trim();
              vars.put(varName, res);
          }
  
          return res;
  
      }
docs: {@inheritDoc}