docs: public void registerOperator(final String name, final Class<?> operatorSubclass) throws Exception
      {
          final String token = name.toLowerCase();
          if (operatorMap.containsKey(name))
              throw new Exception("duplicate operator: " + token);
          try
          {
              operatorMap.put(token, operatorSubclass.getConstructor(new Class<?>[] {
                      EquPart.class
              }));
          } catch (final Exception e)
          {
              throw new Exception("register operator: " + token, e);
          }
      }