return astRewrite;
}
// add required=false to annotation
else {
NormalAnnotation newAnnotation = ast.newNormalAnnotation();
newAnnotation.setTypeName(ast.newSimpleName(annotation.getTypeName().getFullyQualifiedName()));
MemberValuePair requiredValue = ast.newMemberValuePair();
requiredValue.setName(ast.newSimpleName("required"));
requiredValue.setValue(ast.newBooleanLiteral(false));