### Question:
ScreenshotFileProvider { String cleanseTag(@NonNull String tag) { final String originalTag = tag; tag = tag.toLowerCase().replaceAll(" ", "_").replaceAll("[^A-Za-z0-9_]", ""); if (!originalTag.equals(tag)) { log("Cleansed Tag: [" + originalTag + "] -> [" + tag + "]"); } return tag; }  File getScreenshotFile(@NonNull String tag); abstract void clearPreviousScreenshots();  }### Answer:
@Test public void testCleanseTag() { String cleansed = new ScreenshotFileProviderNoOp().cleanseTag("a b c * $ ! d"); assertThat(cleansed).isEqualTo("a_b_c____d"); }