@Override
      public void visitLeaf(LeafElement leaf) {
        if (!REF_FILTER.contains(leaf.getElementType())) {
          String leafText = leaf.getText();
          if (buffer.length() > 0 && !leafText.isEmpty() && Character.isJavaIdentifierPart(leafText.charAt(0))) {
            char lastInBuffer = buffer.charAt(buffer.length() - 1);
            if (lastInBuffer == '?' || Character.isJavaIdentifierPart(lastInBuffer)) {
              buffer.append(" ");
            }
          }

          buffer.append(leafText);
        }
      }
@Override
      public void visitLeaf(LeafElement leaf)