Sergey Pak developed headless mode support for TestDialogManager in the JetBrains/intellij-community repository, focusing on improving automated testing workflows. By enabling TestDialogManager.setTestDialog to function without a GUI, Sergey aligned its behavior with MessagesServiceImpl.isApplicationInUnitTestOrHeadless, ensuring consistent test environments across modules. This Java-based enhancement targeted feature parity and testability, allowing dialog tests to run reliably in continuous integration pipelines without manual intervention. The work emphasized software development best practices and unit testing, reducing dependencies on graphical interfaces and accelerating iteration cycles. Although the contribution was scoped to a single feature, it addressed a nuanced challenge in automated test infrastructure.