docs: public static void makePrefix(CSTNode node, boolean throwIfInvalid) {
  
          switch (node.getMeaning()) {
              case PLUS:
                  node.setMeaning(PREFIX_PLUS);
                  break;
  
              case MINUS:
                  node.setMeaning(PREFIX_MINUS);
                  break;
  
              case PLUS_PLUS:
                  node.setMeaning(PREFIX_PLUS_PLUS);
                  break;
  
              case MINUS_MINUS:
                  node.setMeaning(PREFIX_MINUS_MINUS);
                  break;
  
              default:
                  if (throwIfInvalid) {
                      throw new GroovyBugError("cannot convert to prefix for type [" + node.getMeaning() + "]");
                  }
          }
  
      }