one-liners for the remaining top-50 dart:core classes

sdk/lib/core/set.dart

Index: sdk/lib/core/set.dart
diff --git a/sdk/lib/core/set.dart b/sdk/lib/core/set.dart
index aaab5ec465ecf0a14e9a370ba220c8f0030d694f..bd6aded52d97a053b2f7e676f282564fe48c207e 100644
--- a/sdk/lib/core/set.dart
+++ b/sdk/lib/core/set.dart
@@ -5,13 +5,13 @@
 part of dart.core;
 
 /**
- * A `Set` is a collection of elements where each element can occur only once.
+ * A collection of objects in which each object can occur only once.
  *
  * That is, for each object of the element type, the object is either considered
- * to be in the set, or it is not in the set.
+ * to be in the set, or to _not_ be in the set. 

[Lasse Reichstein Nielsen, 2016/08/31 18:57:37]

Trailing space, please remove.

  *
  * Set implementations may consider some elements indistinguishable. These
- * objects will be treated as being the same for any operation on the set.
+ * elements are treated as being the same for any operation on the set.
  *
  * The default `Set` implementation, [HashSet], considers objects
  * indistinguishable if they are equal with regard to [Object.operator==].