### Question:
TezUtils { @Private public static String cleanVertexName(String vertexName) { return sanitizeString(vertexName).substring(0, vertexName.length() > MAX_VERTEX_NAME_LENGTH ? MAX_VERTEX_NAME_LENGTH : vertexName.length()); }  static void addUserSpecifiedTezConfiguration(Configuration conf); static ByteString createByteStringFromConf(Configuration conf); static byte[] createUserPayloadFromConf(Configuration conf); static Configuration createConfFromByteString(ByteString byteString); static Configuration createConfFromUserPayload(byte[] bb); static byte[] compressBytes(byte[] inBytes); static byte[] uncompressBytes(byte[] inBytes); @Private static String cleanVertexName(String vertexName); static void updateLoggers(String addend); static BitSet fromByteArray(byte[] bytes); static byte[] toByteArray(BitSet bits); static String getContainerLogDir(); @Private
  static final int MAX_VERTEX_NAME_LENGTH; }### Answer:
@Test public void testCleanVertexName() { String testString = "special characters & spaces and longer than " + TezUtils.MAX_VERTEX_NAME_LENGTH + " characters"; Assert.assertTrue(testString.length() > TezUtils.MAX_VERTEX_NAME_LENGTH); String cleaned = TezUtils.cleanVertexName(testString); Assert.assertTrue(cleaned.length() <= TezUtils.MAX_VERTEX_NAME_LENGTH); Assert.assertFalse(cleaned.contains("\\s+")); Assert.assertTrue(cleaned.matches("\\w+")); }