在Visual Studio中使用2个项目和2个测试项目时，如何避免重复设置？

Following my previous question, now I have 2 projects: one Console Project and a Library Project. They also have their respective unit test projects. When I run a test for the console project that uses a method from the library project and the library project needs an app.config setting, that setting must be in the console test project's app.config. What I have to do to make it read the setting from the library project app.config, so then I do not have to duplicate the setting across multiple app.config?, now I have 2 pr