private void updatePackageStatement(
     CompilationUnit astCU, String[] pkgName, ASTRewrite rewriter, ICompilationUnit cu)
     throws JavaModelException {
   boolean defaultPackage = pkgName.length == 0;
   AST ast = astCU.getAST();
   if (defaultPackage) {
     // remove existing package statement
     PackageDeclaration pkg = astCU.getPackage();
     if (pkg != null) {
       int pkgStart;
       Javadoc javadoc = pkg.getJavadoc();
       if (javadoc != null) {
         pkgStart = javadoc.getStartPosition() + javadoc.getLength() + 1;
       } else {
         pkgStart = pkg.getStartPosition();
       }
       int extendedStart = astCU.getExtendedStartPosition(pkg);
       if (pkgStart != extendedStart) {
         // keep the comments associated with package declaration
         // see https://bugs.eclipse.org/bugs/show_bug.cgi?id=247757
         String commentSource = cu.getSource().substring(extendedStart, pkgStart);
         ASTNode comment =
             rewriter.createStringPlaceholder(commentSource, ASTNode.PACKAGE_DECLARATION);
         rewriter.set(astCU, CompilationUnit.PACKAGE_PROPERTY, comment, null);
       } else {
         rewriter.set(astCU, CompilationUnit.PACKAGE_PROPERTY, null, null);
       }
     }
   } else {
     org.eclipse.jdt.core.dom.PackageDeclaration pkg = astCU.getPackage();
     if (pkg != null) {
       // rename package statement
       Name name = ast.newName(pkgName);
       rewriter.set(pkg, PackageDeclaration.NAME_PROPERTY, name, null);
     } else {
       // create new package statement
       pkg = ast.newPackageDeclaration();
       pkg.setName(ast.newName(pkgName));
       rewriter.set(astCU, CompilationUnit.PACKAGE_PROPERTY, pkg, null);
     }
   }
 }
 public boolean visit(PackageDeclaration node) {
   new JavaNode(
       getCurrentContainer(), JavaNode.PACKAGE, null, node.getStartPosition(), node.getLength());
   return false;
 }