我正在使用rubymine运行测试用例。每当我运行单独的测试用例时它都有效，但是当我同时运行所有测试用例时，我的一个测试用例就失败了。
以下是我得到的错误。
Fail to load: D:/image-resource-planning/test/models/fact_revenue_cost_test.rb:1
Exception message: superclass mismatch for class FactRevenueCostTest
["D:/image-resource-planning/test/models/fact_revenue_cost_test.rb:4:in `(root)'", "org/jruby/RubyKernel.java:1065:in `require'", "C:/jruby-1.7.16/lib/ruby/gems/shared/gems/activesupport-4.2.0/lib/active_support/dependencies.rb:274:in `require'", "C:/jruby-1.7.16/lib/ruby/gems/shared/gems/activesupport-4.2.0/lib/active_support/dependencies.rb:240:in `load_dependency'", "C:/jruby-1.7.16/lib/ruby/gems/shared/gems/activesupport-4.2.0/lib/active_support/dependencies.rb:274:in `require'", "C:/Program Files (x86)/JetBrains/RubyMine 2016.2.4/rb/testing/runner/tunit_or_minitest_in_folder_runner.rb:1:in `(root)'", "org/jruby/RubyArray.java:1613:in `each'", "C:/Program Files (x86)/JetBrains/RubyMine 2016.2.4/rb/testing/runner/tunit_or_minitest_in_folder_runner.rb:51:in `require_all_test_scripts'", "C:/Program Files (x86)/JetBrains/RubyMine 2016.2.4/rb/testing/runner/tunit_or_minitest_in_folder_runner.rb:44:in `require_all_test_scripts'", "org/jruby/RubyKernel.java:1081:in `load'", "-e:1:in `(root)'"]