// post: output is closed
public void close() {
if (numDigits > 0) flush();
try {
output.close();
} catch (IOException e) {
throw new RuntimeException(e.toString());
}
}
// post: writes given bit to output
public void writeBit(int bit) {
if (bit < 0 || bit > 1) throw new IllegalArgumentException("Illegal bit: " + bit);
digits += bit << numDigits;
numDigits++;
if (numDigits == BYTE_SIZE) flush();
}
