```
@Documented
@Inherited
@Retention(RUNTIME)
@Target({METHOD,FIELD})
public @interface ReplaceInRegistry
```
@ReplaceInRegistry is an annotation used to mark all the methods and fields whose return value or value should replace an existing bean in the registry. It is meant to be used to replace a real implementation of a service with a mock or a test implementation.
If a field is marked with the annotation @ReplaceInRegistry, the name and the type of the field are used to identify the bean to replace, and the value of the field is the new value of the bean. The field can be in the test class or in a parent class.
In the next example, the annotation ReplaceInRegistry on the field myGreetings of type Greetings indicates that the bean with the same name and type should be replaced by an instance of CustomGreetings.
```
 

 @CamelMainTest
 class SomeTest {

     @ReplaceInRegistry
     Greetings myGreetings = new CustomGreetings("Willy");

     // The rest of the test class
 }
 
 
```
If a method is marked with the annotation @ReplaceInRegistry, the name and the return type of the method are used to identify the bean to replace, and the return value of the method is the new value of the bean. The method can be in the test class or in a parent class.
In the next example, the annotation ReplaceInRegistry on the method myGreetings whose return type is Greetings indicates that the bean with the same name and type should be replaced by an instance of CustomGreetings.
```
 

 @CamelMainTest
 class SomeTest {

     @PropertyInject("name")
     String name;

     @ReplaceInRegistry
     Greetings myGreetings() {
         return new CustomGreetings(name);
     }

     // The rest of the test class
 }
 
 
```
This annotation can be used in @Nested test classes. The @ReplaceInRegistry annotations of outer classes are processed before the @ReplaceInRegistry annotations of inner classes.

Annotation Type ReplaceInRegistry