def METHOD_NAME(self):
    """
    Verify that we truncate the preference value if it is too long.
    """
    MAX_STRING_LENGTH = 12500
    OVERSIZE_STRING_LENGTH = MAX_STRING_LENGTH + 10
    self.user_preference.value = "z" * OVERSIZE_STRING_LENGTH
    self.user_preference.save()
    self.assert_user_setting_event_emitted(
        setting=self.TEST_KEY, old=self.TEST_VALUE, new="z" * MAX_STRING_LENGTH, truncated=["new"]
    )
    self.user_preference.value = "x" * OVERSIZE_STRING_LENGTH
    self.user_preference.save()
    self.assert_user_setting_event_emitted(
        setting=self.TEST_KEY, old="z" * MAX_STRING_LENGTH, new="x" * MAX_STRING_LENGTH, truncated=["old", "new"]
    )