code: @Deprecated
      public static ExpressionEvaluator getEvaluatorByName(String name) throws JspException {
          try {
              ExpressionEvaluator evaluator = nameMap.get(name);
              if (evaluator == null) {
                  nameMap.putIfAbsent(name, (ExpressionEvaluator) Class.forName(name).newInstance());
                  evaluator = nameMap.get(name);
              }
              return evaluator;
          } catch (ClassCastException ex) {
              // just to display a better error message
              throw new JspException("invalid ExpressionEvaluator: " + name, ex);
          } catch (ClassNotFoundException ex) {
              throw new JspException("couldn't find ExpressionEvaluator: " + name, ex);
          } catch (IllegalAccessException ex) {
              throw new JspException("couldn't access ExpressionEvaluator: " + name, ex);
          } catch (InstantiationException ex) {
              throw new JspException("couldn't instantiate ExpressionEvaluator: " + name, ex);
          }
      }
docs: Gets an ExpressionEvaluator from the cache, or seeds the cache
  if we haven't seen a particular ExpressionEvaluator before.