Resolve a Testability Obstacle Introduce the smallest behavior-preserving seam needed to test a specific C# behavior, then add deterministic tests that prove both the behavior and the seam. The production edit is a means to the requested test, not an invitation to redesign adjacent code. When to Use - A requested test would otherwise read/write the real filesystem. - Behavior depends on the current time, delay, random value, environment, console, process, or another ambient dependency. - The user explicitly permits or requests a safe production seam. - Existing tests cannot control a dependen…