AssertSocketSameNetNS makes a best-effort attempt to assert that conn is in the same network namespace as the current goroutine's thread.

SetupTestOSContext joins the current goroutine to a new network namespace, and returns its associated teardown function.

SetupTestOSContextEx joins the current goroutine to a new network namespace.

OSContext is a handle to a test OS context.

Logger is used to log non-fatal messages during tests.