How to use the binary.ByteArray function in binary

assert.isEqual(0, b1.length);
    b1.length = 123;
    assert.isEqual(0, b1.length);
    
    // ByteString(byteString)
    // Copies byteString.
    var b2 = new ByteString(new ByteString(testArray));
    assert.isEqual(testArray.length, b2.length);
    b2.length = 123;
    assert.isEqual(testArray.length, b2.length);
    assert.isEqual(1, b2.get(0));
    assert.isEqual(4, b2.get(3));
    
    // ByteString(byteArray)
    // Use the contents of byteArray.
    var b2 = new ByteString(new ByteArray(testArray));
    assert.isEqual(testArray.length, b2.length);
    b2.length = 123;
    assert.isEqual(testArray.length, b2.length);
    assert.isEqual(1, b2.get(0));
    assert.isEqual(4, b2.get(3));
    
    // ByteString(arrayOfNumbers)
    // Use the numbers in arrayOfNumbers as the bytes.
    // If any element is outside the range 0...255, an exception (TODO) is thrown.
    var b3 = new ByteString(testArray);
    assert.isEqual(testArray.length, b3.length);
    b3.length = 123;
    assert.isEqual(testArray.length, b3.length);
    assert.isEqual(1, b3.get(0));
    assert.isEqual(4, b3.get(3));
};

exports.testDecodeToString = function() {
    assert.isEqual("hello world", new ByteArray("hello world", "US-ASCII").decodeToString("US-ASCII"));
    
    assert.isEqual("I ♥ JS", new ByteArray("I ♥ JS", "UTF-8").decodeToString("UTF-8"));
    
    assert.isEqual("\u0024", new ByteArray([0x24]).decodeToString("UTF-8"));
    assert.isEqual("\u00A2", new ByteArray([0xC2,0xA2]).decodeToString("UTF-8"));
    assert.isEqual("\u20AC", new ByteArray([0xE2,0x82,0xAC]).decodeToString("UTF-8"));
    // FIXME:
    //assert.isEqual("\u10ABCD", (new ByteArray([0xF4,0x8A,0xAF,0x8D])).decodeToString("UTF-8"));
    
    assert.isEqual("\u0024", new ByteArray("\u0024", "UTF-8").decodeToString("UTF-8"));
    assert.isEqual("\u00A2", new ByteArray("\u00A2", "UTF-8").decodeToString("UTF-8"));
    assert.isEqual("\u20AC", new ByteArray("\u20AC", "UTF-8").decodeToString("UTF-8"));
    assert.isEqual("\u10ABCD", new ByteArray("\u10ABCD", "UTF-8").decodeToString("UTF-8"));
    
    assert.isEqual("\u0024", new ByteArray("\u0024", "UTF-16").decodeToString("UTF-16"));
    assert.isEqual("\u00A2", new ByteArray("\u00A2", "UTF-16").decodeToString("UTF-16"));
    assert.isEqual("\u20AC", new ByteArray("\u20AC", "UTF-16").decodeToString("UTF-16"));
    assert.isEqual("\u10ABCD", new ByteArray("\u10ABCD", "UTF-16").decodeToString("UTF-16"));
};

exports.testByteArrayConcat = function() {

    var b = new ByteArray();
    
    var b1 = b.concat(new ByteArray([1,2,3]));
    assert.isEqual(3, b1.length);
    assert.isEqual(1, b1.get(0));
    assert.isEqual(2, b1.get(1));
    assert.isEqual(3, b1.get(2));
    
    var b2 = b1.concat(new ByteString([4,5,6]));
    assert.isEqual(6, b2.length);
    assert.isEqual(1, b2.get(0));
    assert.isEqual(3, b2.get(2));
    assert.isEqual(4, b2.get(3));
    assert.isEqual(6, b2.get(5));
    
    var b3 = b2.concat([b, b1, b2, new ByteString(), new ByteArray()]);
    assert.isEqual(b.length + b1.length + b2.length + b2.length, b3.length);

exports.testByteArrayPush = function() {
    var b1 = new ByteArray();
    assert.isEqual(3, b1.push(1,2,3));
    assert.isEqual(3, b1.length);
    assert.isEqual(1, b1.get(0));
    assert.isEqual(2, b1.get(1));
    assert.isEqual(3, b1.get(2));
    
    var b2 = new ByteArray([7, 8, 9]);
    assert.isEqual(6, b1.push.apply(b1, b2.toArray()));
    assert.isEqual(6, b1.length);
    assert.isEqual(7, b1.get(3));
    assert.isEqual(8, b1.get(4));
    assert.isEqual(9, b1.get(5));
};

exports.testCopyTreeAsFiles = function() {
    assert.isTrue(Files.exists(Paths.get(testFile)));

    var stream = fs.open(testFile, "wb");
    var ba = new ByteArray([0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]);
    try {
        stream.write(ba);
        stream.flush();
    } finally {
        stream.close();
        assert.isTrue(stream.closed());
    }

    var file2 = String(Files.createTempFile("copyofcopytest", ".txt").toAbsolutePath());
    fs.copyTree(testFile, file2);

    assert.isTrue(Files.exists(Paths.get(testFile)));
    assert.isTrue(Files.exists(Paths.get(file2)));
    assert.isFalse(Files.isDirectory(Paths.get(testFile)));
    assert.isFalse(Files.isDirectory(Paths.get(file2)));

exports.testToArrayEncodings = function() {
    var a1;
    
    a1 = new ByteArray("\u0024\u00A2\u20AC", "UTF-8").toArray("UTF-8");
    assert.isEqual(3, a1.length);
    assert.isEqual(0x24, a1[0]);
    assert.isEqual(0xA2, a1[1]);
    assert.isEqual(0x20AC, a1[2]);
    
    a1 = new ByteArray("\u0024\u00A2\u20AC", "UTF-16").toArray("UTF-16");
    assert.isEqual(3, a1.length);
    assert.isEqual(0x24, a1[0]);
    assert.isEqual(0xA2, a1[1]);
    assert.isEqual(0x20AC, a1[2]);
};

exports.testToByteString = function() {
    var b1 = new ByteArray([1,2,3]),
        b2 = b1.toByteString();
        
    assert.isEqual(b1.length, b2.length);
    assert.isEqual(b1.get(0), b2.get(0));
    assert.isEqual(b1.get(2), b2.get(2));
    
    assert.isEqual(1, b1.get(0));
    assert.isEqual(1, b2.get(0));
    
    b1.set(0, 10);
    
    assert.isEqual(10, b1.get(0));
    assert.isEqual(1, b2.get(0));
};

var ByteArray = require('binary').ByteArray;

var n = 128 * 1024;
var b = new ByteArray(n);
for (var i = 0; i < n; i++) {
  b[i] = Math.floor(32 + (127 - 32) * Math.random());
}
exports.app = function(request) {
  return {
    status:200,
    headers:{
      "Content-Type":"text/plain"
    },
    body:[b.decodeToString("ascii")]
  };
};

exports.createSalt = function() {
    var salt = new ByteArray(8);
    var random = SecureRandom.getInstance("SHA1PRNG");
    random.nextBytes(salt);
    return salt;
};