Issue373.java:16:13: compiler.err.proc.messager: [override.return] Incompatible return type.
found   : Set<Entry<String, String>>
required: Set<Entry<@KeyFor("this") String, String>>
Consequence: method in Issue373
  Set<Entry<String, String>> entrySet(Issue373 this)
cannot override method in AbstractMap<String, String>
  Set<Entry<@KeyFor("this") String, String>> entrySet(AbstractMap<String, String> this)
1 error
