### Question:
DittedBitSequence { public int getNumUncertainBits() { int popcnt = 0; for (byte dit : dits) { popcnt += popcount[0xff & dit]; } return 8 * dits.length - popcnt; } DittedBitSequence();  DittedBitSequence(String dittedBitData);  DittedBitSequence(String dittedBitData, boolean hex);  DittedBitSequence(DittedBitSequence op2);  DittedBitSequence(byte[] bytes);  DittedBitSequence(byte[] bytes, byte[] mask);  DittedBitSequence(DittedBitSequence s1, DittedBitSequence s2); byte[] getValueBytes(); byte[] getMaskBytes(); @Override int hashCode(); @Override boolean equals(Object obj); DittedBitSequence concatenate(DittedBitSequence op2); boolean isMatch(int pos, int val); int getIndex(); int getSize(); int getNumFixedBits(); int getNumUncertainBits(); void writeBits(StringBuffer buf); @Override String toString(); String getHexString(); int getNumInitialFixedBits(int marked); static int[] popcount; }### Answer:
@Test public void testGetNumUncertainBits() { DittedBitSequence dSeq = new DittedBitSequence("0xffff", true); assertEquals(dSeq.getNumUncertainBits(), 0); dSeq = new DittedBitSequence("0x0000", true); assertEquals(dSeq.getNumUncertainBits(), 0); byte bits = (byte) 0xa0; byte dits = (byte) 0x55; dSeq = new DittedBitSequence(new byte[] { bits }, new byte[] { dits }); assertEquals(dSeq.getNumUncertainBits(), 4); }