docs: public void exitBlock() {
          if (open == 0) {
              return;
          }
  
          if (open < 0) {
              throw new IllegalStateException("Parser is no longer nested in any blocks at the level in which it was " +
                      "created. You must create a new block aware parser to track the levels above this one.");
          }
  
          while (open > 0) {
              Token t = delegate.nextToken();
              if (t == null) {
                  // handle EOF?
                  return;
              }
              updateLevelBasedOn(t);
          }
      }