Improved phrasing

Froussios · Froussios · commit 1e7adeaac1d3 · 2015-04-26T21:10:07.000+02:00
diff --git a/Part 3 - Taming the sequence/7. Custom operators.md b/Part 3 - Taming the sequence/7. Custom operators.md
@@ -258,7 +258,7 @@ Observable.range(0, 5)
 	.subscribe(System.out::println);
 ```
 
-There are a few things to consider when doing manual pushes to subscribers
+When doing manual pushes to subscribers, like we do when implementing `Observable.Operator`, there are a few things to consider
 * A subscriber is free to unsubscribe. Don't push without checking first: `!subscriber.isUnsubscribed()`.
 * You are responsible for complying with the Rx contract: any number of `onNext` notifications, optionally followed by a single `onCompleted` or `onError`.
 * If you are going to use asynchronous operations and scheduling, use the [Schedulers](/Part%204%20-%20Concurrency/1.%20Scheduling%20and%20threading.md#Schedulers) of Rx. That will allow your operator to become [testable](/Part%204%20-%20Concurrency/2.%20Testing%20Rx.md#testscheduler).
