@Override
  public ASTNode findChildByRole(int role) {
    LOG.assertTrue(ChildRole.isUnique(role));
    switch(role){
      case ChildRole.PACKAGE_KEYWORD:
        return findChildByType(JavaTokenType.PACKAGE_KEYWORD);

      case ChildRole.PACKAGE_REFERENCE:
        return findChildByType(JavaElementType.JAVA_CODE_REFERENCE);

      case ChildRole.CLOSING_SEMICOLON:
        return TreeUtil.findChildBackward(this, JavaTokenType.SEMICOLON);

      case ChildRole.MODIFIER_LIST:
        return findChildByType(JavaElementType.MODIFIER_LIST);

      default:
        return null;
    }
  }
@Override
  public ASTNode findChildByRole(int role)