anchor.diff:          }
       }
   
  -    private static final Map<String, String> PAREN_MAP = Collections.unmodifiableMap(new HashMap<String, String>() {
  -        {
  -            put("(", ")");
  -            put("[", "]");
  -            put("{", "}");
  -        }
  -    });
  +    private static final Map<String, String> PAREN_MAP =
  +        Maps.of(
  +            "(", ")",
  +            "[", "]",
  +            "{", "}"
  +        );
   
       protected void enterParenCallback(String text) {}
   
  
positive.code: RollBackOne
      :   . {
              // a trick to handle GStrings followed by EOF properly
              if (EOF == _input.LA(1) && ('"' == _input.LA(-1) || '/' == _input.LA(-1))) {
                  setType(GStringEnd);
              } else {
                  setChannel(HIDDEN);
  
negative.code: }
  
  @header {
      import java.util.Deque;
      import java.util.ArrayDeque;
      import java.util.Map;
  