androidx.appcompat.app.AppCompatActivityThe typo was in line 19:

[jessore7400kabir-gif]

The typo was in line 19:
https://github.com/android/snippets/blob/main/misc/src/androidTest/java/com/example/snippets/DeviceCompatibilityModeTestJavaSnippets.java#L19

import androidx.appcompat.app.AppCompatActivity
import androidx.test.core.app.ActivityScenario;
import androidx.test.ext.junit.rules.ActivityScenarioRule;

(note the lack of a semicolon at the end of the first line).

But when I fixed that typo, the file still wouldn't compile, because isLetterBoxed() expects to be passed an AppCompatActivity but it's actually being passed a MainActivity.

When I changed the isLetterBoxed method to be passed a MainActivity, everything compiles -- but since the file no longer needs AppCompatActivity, AndroidStudio removed that "import AppCompatActivity" line, so the typo fix went away.

...just to confirm, when you submitted it, did you compile the AndroidTest module? I don't see how it could have compiled with that missing semicolon.

Originally posted by @asolovay in #575 (comment)