whilie calling getBean( with Impl class) then getting below exception?

Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.dav.spring.domain.HelloWorldImpl] is defined at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:319) at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:985) at Test.main(Test.java:24)

interface :

public interface HelloWorld {
void sayHello(String helloStr);}

impl class :

package com.dav.spring.domain;

public class HelloWorldImpl implements HelloWorld {

@Override
public void sayHello(String helloStr) {
    System.out.println("Welcome to spring 4" + helloStr);
}

}

Configuraion Class:

@Configuration
public class MyConfiguration {

@Bean(name = "helloworld")
@Description("This is newly added in spring 4")
@Scope("prototype") // If removed this, it's fine.
HelloWorld getHelloWorldImpl() {
    return new HelloWorldImpl();
}
}

Main class:

public class Test {

public static void main(String[] args) {
    // We did configuration by using JavaConfiguration so
    // we should use like this
    AnnotationConfigApplicationContext antConf = new AnnotationConfigApplicationContext(
            MyConfiguration.class);

    HelloWorld byParentClass = antConf.getBean(HelloWorld.class);
    byParentClass.sayHello("  Raju");

    System.out.println(byParentClass.hashCode());

    HelloWorld byBeanName = (HelloWorld) antConf.getBean("helloworld");
    byBeanName.sayHello("  Chinna");
    System.out.println(byBeanName.hashCode());

    HelloWorldImpl byImplClass = antConf.getBean(HelloWorldImpl.class);
    byImplClass.sayHello("  Daveedu Raju");
}

}