test, inline `DeveloperWithAggregate`, which is used by a single test.

activerecord/test/cases/base_test.rb

@@ -774,8 +774,14 @@ def test_dup
     assert_equal("c", duped_topic.title)
   end
 
+  DeveloperSalary = Struct.new(:amount)
   def test_dup_with_aggregate_of_same_name_as_attribute
-    dev = DeveloperWithAggregate.find(1)
+    developer_with_aggregate = Class.new(ActiveRecord::Base) do
+      self.table_name = 'developers'
+      composed_of :salary, :class_name => 'BasicsTest::DeveloperSalary', :mapping => [%w(salary amount)]
+    end
+
+    dev = developer_with_aggregate.find(1)
     assert_kind_of DeveloperSalary, dev.salary
 
     dup = nil

activerecord/test/models/developer.rb

@@ -76,12 +76,6 @@ class AuditLog < ActiveRecord::Base
   belongs_to :unvalidated_developer, :class_name => 'Developer'
 end
 
-DeveloperSalary = Struct.new(:amount)
-class DeveloperWithAggregate < ActiveRecord::Base
-  self.table_name = 'developers'
-  composed_of :salary, :class_name => 'DeveloperSalary', :mapping => [%w(salary amount)]
-end
-
 class DeveloperWithBeforeDestroyRaise < ActiveRecord::Base
   self.table_name = 'developers'
   has_and_belongs_to_many :projects, :join_table => 'developers_projects', :foreign_key => 'developer_id'