Rewrite doc comment to refer to TypeError (#57)
This will be the type going forward. Keep a reference to `CastError` for
now, we can drop it after a few SDK releases.
diff --git a/lib/stream_channel.dart b/lib/stream_channel.dart
index 5693792..4722aa3 100644
@@ -126,8 +126,9 @@
/// Returns a copy of this with the generic type coerced to [S].
/// If any events emitted by [stream] aren't of type [S], they're converted
- /// into [CastError] events. Similarly, if any events are added to [sink] that
- /// aren't of type [S], a [CastError] is thrown.
+ /// into [TypeError] events (`CastError` on some SDK versions). Similarly, if
+ /// any events are added to [sink] that aren't of type [S], a [TypeError] is
+ /// thrown.