### Question:
ReadWrite { public static void writeLong (final ByteBuffer buffer, final long value, final int index) { final byte[] bytes = longToBytes(value); buffer.position(index); for (int i = 0; i < bytes.length; ++i) buffer.put(bytes[i]); } private  ReadWrite(); static final int readOneByteInt(ByteBuffer buffer, int start); static final int readOneByteInt(byte[] array, int start); static final int readTwoByteInt(ByteBuffer buffer, int start); static final int readTwoByteInt(byte[] array, int start); static final int readThreeByteInt(ByteBuffer buffer, int start); static final int readThreeByteInt(byte[] array, int start); static final int readFourByteInt(ByteBuffer buffer, int start); static final int readFourByteInt(byte[] array, int start); static ByteBuffer[] stringToTextDataSegments(String string, int bufferSize); static final void appendTextDataSegmentToStringBuffer(final ByteBuffer byteBuffer, final StringBuilder stringBuilder); static final void writeInt(int value, final ByteBuffer buffer, int start); static String byteBufferToString(final ByteBuffer buffer); static byte[] longToBytes(final long value); static void writeLong(final ByteBuffer buffer, final long value, final int index); static void writeTwoByteInt(final ByteBuffer buffer, final int value, final int index); static void writeThreeByteInt(final ByteBuffer buffer, final int value, final int index); static long readUnsignedInt(final ByteBuffer buffer, final int start);  }### Answer:
@Test public void testWriteLong () { ByteBuffer longBuffer = ByteBuffer.allocate(8); ReadWrite.writeLong(longBuffer, 42, 0); }