Fix Memoizable test

lib/mutant/matcher/method/instance.rb

@@ -12,10 +12,12 @@ module Mutant
         # @param [UnboundMethod] method
         #
         # @return [Matcher::Method::Instance]
+        #
+        # :reek:ManualDispatch
         def self.new(scope, target_method)
           name = target_method.name
           evaluator =
-            if scope.include?(Memoizable) && scope.memoized?(name)
+            if scope.respond_to?(:memoized?) && scope.memoized?(name)
               Evaluator::Memoized
             else
               Evaluator

test_app/lib/test_app.rb

@@ -7,7 +7,7 @@ $VERBOSE = false
 # Namespace for test application
 module TestApp
   module InstanceMethodTests
-    class WithMemoizer
+    module WithMemoizer
       include Adamantium
 
       def bar; end; def baz; end