removing unnecessary root parameter on fragment cache

Author: joaomdmoura

lib/active_model/serializer/adapter.rb

@@ -48,7 +48,7 @@ def cache_check(serializer)
             yield
           end
         elsif is_fragment_cached?
-          FragmentCache.new(self, @cached_serializer, @options, @root).fetch
+          FragmentCache.new(self, @cached_serializer, @options).fetch
         else
           yield
         end

lib/active_model/serializer/adapter/fragment_cache.rb

@@ -5,8 +5,7 @@ class FragmentCache
 
         attr_reader :serializer
 
-        def initialize(adapter, serializer, options, root)
-          @root       = root
+        def initialize(adapter, serializer, options)
           @options    = options
           @adapter    = adapter
           @serializer = serializer

test/adapter/fragment_cache_test.rb

@@ -8,7 +8,7 @@ def setup
           @role            = Role.new(name: 'Great Author', description:nil)
           @role.author     = [@author]
           @role_serializer = RoleSerializer.new(@role)
-          @role_hash       = FragmentCache.new(RoleSerializer.adapter.new(@role_serializer), @role_serializer, {}, nil)
+          @role_hash       = FragmentCache.new(RoleSerializer.adapter.new(@role_serializer), @role_serializer, {})
         end
 
         def test_fragment_fetch_with_virtual_attributes