Netflix/RxJava — pull request #1569 by benjchristensen (2014-08-12 05:21:52+00:00)
Title: Compose/Transform Covariance

Failing test while exploring generic variance for https://github.com/Netflix/RxJava/issues/1416

Code like this makes these generics work:

```java
@Test
public void testCovarianceOfCompose() {
Observable movie = Observable. from(new HorrorMovie());
movie.compose(new Transformer() {

@Override
public Observable call(Observable t1) {
return Observable.from(new Movie());
}

});
}

@Test
public void testCovarianceOfCompose2() {
Observable movie = Observable. from(new HorrorMovie());
movie.compose(new Transformer() {

@Override
public Observable call(Observable t1) {
return Observable.from(new HorrorMovie());
}

});
}
```

however, I couldn't get the `compose`/`Transformer` types to correctly work.

Anyone else want to help figure out generics for this?

See https://github.com/Netflix/RxJava/blob/master/rxjava-core/src/main/java/rx/Observable.java#L195