### Question:
Util { @VisibleForTesting static byte[] ascii8To6bitBin(byte[] toDecBytes) { byte[] convertedBytes = new byte[toDecBytes.length]; int sum = 0; int _6bitBin = 0; for (int i = 0; i < toDecBytes.length; i++) { sum = 0; _6bitBin = 0; if (toDecBytes[i] < 48) { throw new AisParseException(AisParseException.INVALID_CHARACTER + " " + (char) toDecBytes[i]); } else { if (toDecBytes[i] > 119) { throw new AisParseException(AisParseException.INVALID_CHARACTER + " " + (char) toDecBytes[i]); } else { if (toDecBytes[i] > 87) { if (toDecBytes[i] < 96) { throw new AisParseException(AisParseException.INVALID_CHARACTER + " " + (char) toDecBytes[i]); } else { sum = toDecBytes[i] + 40; } } else { sum = toDecBytes[i] + 40; } if (sum != 0) { if (sum > 128) { sum += 32; } else { sum += 40; } _6bitBin = sum & 0x3F; convertedBytes[i] = (byte) _6bitBin; } } } } return convertedBytes; } private  Util(); static void checkLatLong(double lat, double lon); static void checkLat(double lat); static void checkLong(double lon); static void checkArgument(boolean b, String message); static AisExtractorFactory getAisExtractorFactory(); static void checkMessageId(int messageId, AisMessageType... messageTypes); static boolean areEqual(int i, int j); static boolean isClassAPositionReport(int messageId);  }### Answer:
@Test(expected = AisParseException.class) public void testAscii8To6BitBinaryIllegalCharacterLowThrowsException() { Util.ascii8To6bitBin(new byte[] { 0 }); }
@Test(expected = AisParseException.class) public void testAscii8To6BitBinaryIllegalCharacterHighThrowsException() { Util.ascii8To6bitBin(new byte[] { 120 }); }
@Test(expected = AisParseException.class) public void testAscii8To6BitBinaryIllegalCharacterMediumThrowsException() { Util.ascii8To6bitBin(new byte[] { 88 }); }