/** Renames the main type in <code>cu</code>. */
 private void updateTypeName(
     ICompilationUnit cu,
     CompilationUnit astCU,
     String oldName,
     String newName,
     ASTRewrite rewriter)
     throws JavaModelException {
   if (newName != null) {
     String oldTypeName = Util.getNameWithoutJavaLikeExtension(oldName);
     String newTypeName = Util.getNameWithoutJavaLikeExtension(newName);
     AST ast = astCU.getAST();
     // update main type name
     IType[] types = cu.getTypes();
     for (int i = 0, max = types.length; i < max; i++) {
       IType currentType = types[i];
       if (currentType.getElementName().equals(oldTypeName)) {
         AbstractTypeDeclaration typeNode =
             (AbstractTypeDeclaration) ((JavaElement) currentType).findNode(astCU);
         if (typeNode != null) {
           // rename type
           rewriter.replace(typeNode.getName(), ast.newSimpleName(newTypeName), null);
           // rename constructors
           Iterator bodyDeclarations = typeNode.bodyDeclarations().iterator();
           while (bodyDeclarations.hasNext()) {
             Object bodyDeclaration = bodyDeclarations.next();
             if (bodyDeclaration instanceof MethodDeclaration) {
               MethodDeclaration methodDeclaration = (MethodDeclaration) bodyDeclaration;
               if (methodDeclaration.isConstructor()) {
                 SimpleName methodName = methodDeclaration.getName();
                 if (methodName.getIdentifier().equals(oldTypeName)) {
                   rewriter.replace(methodName, ast.newSimpleName(newTypeName), null);
                 }
               }
             }
           }
         }
       }
     }
   }
 }