This test verifies that reversion panel is shown when user moves carret to previously corrected word using delete key.
After seeing the reversion panel, press down key followed by return key. You should see the phrase "the mesage".
Note, this test can fail due to user specific spell checking data. If the user has previously frequently revert 'message' to 'mesage'. To fix this, remove all files in ~/Library/Spelling, then kill AppleSpell.service process.