lib/pact/matchers/unexpected_key.rb in pact-1.0.38 vs lib/pact/matchers/unexpected_key.rb in pact-1.0.39

@@ -1,20 +1,11 @@
+require 'pact/matchers/difference_indicator'
+
 module Pact
-  class UnexpectedKey
+  class UnexpectedKey < Pact::DifferenceIndicator
 
-    def == other
-      other.is_a? UnexpectedKey
-    end
-
     def to_s
       '<key not to exist>'
     end
 
-    def as_json options = {}
-      to_s
-    end
-
-    def to_json opts = {}
-      as_json.to_json options
-    end
   end
 end
\ No newline at end of file