### Question:
MoveMusic implements ProcessLibrary.StringConverter { public String convert(String s) { if (s.startsWith(origDir)) { String np = destDir + s.substring(origDir.length()); System.out.println(s + " -> " + np); return np; } else { return s; } } MoveMusic(String libraryFilename, String string, String string2); static MoveMusic fromArgs(String[] args); static void main(String[] args); String convert(String s);  }### Answer:
@Test public void testConversion() { MoveMusic mm = new MoveMusic(null, "before-", "after-"); assertEquals("xxx", mm.convert("xxx")); assertEquals("after-xx", mm.convert("before-xx")); assertEquals("after-xx", mm.convert("after-xx")); }