private static void formatTypeParameters(LighterAST tree, LighterASTNode typeParameters, StringBuilder buf) {
    final List<LighterASTNode> children = LightTreeUtil.getChildrenOfType(tree, typeParameters, JavaElementType.TYPE);
    if (children.isEmpty()) return;
    buf.append('<');
    for (int i = 0; i < children.size(); i++) {
      LighterASTNode child = children.get(i);
      formatType(tree, child, buf);
      if (i != children.size() - 1) {
        buf.append(", ");
      }
    }
    buf.append('>');
  }
private static void formatTypeParameters(LighterAST tree, LighterASTNode typeParameters, StringBuilder buf)