anchor.diff:  
   More precisely, you have to master few different variants: if you get the implementation from a factory (like in our example), you have to use the `.toInstance()` DSL, but if you get the implementation from a written class, the correct syntax is `.to()`.
   
  -There is a little other step to do in the actuall `App` class code, and is to retrieve the configured implementation in `AppConfig` within the `App` class itself, using the `Guice::createInjector` function:
  +There is a little other step to do in the actual `App` class code, and is to retrieve the configured implementation in `AppConfig` within the `App` class itself, using the `Guice::createInjector` function:
   ```
   public class App {
       public static void main(String... args) {
  
positive.code: = Dependency Injection demistified
  
  :hp-tags: Java, Guice, Maven
  
  
negative.code:     @Test
      public void test1() {
          repo = new Repository(ds);
          ...test content...
      }
      
      ...other tests...
  }
  ```
  Of course it could be the case to totally create a database mock (e.g. using Mockito) instead of relying on H2 for testing. It does not matter though, because in the `@Before` function we would just write `ds = mock(DataSource.class)` instead of taking an implementation from `Factory`, but the injection of `ds` into `Repository` would still be done in the same way (the tests would not change... nice!).
  