public static void writeLong(byte[] data, int offset, long v)
public static void writeLong(OutputStream os, long v) throws IOException
  public static void writeLong(byte[] data, int offset, long v)  {    data[offset]   = (byte) (0xff & v);    data[offset+1] = (byte) (0xff & (v >>>  8));    data[offset+2] = (byte) (0xff & (v >>> 16));    data[offset+3] = (byte) (0xff & (v >>> 24));    data[offset+4] = (byte) (0xff & (v >>> 32));    data[offset+5] = (byte) (0xff & (v >>> 40));    data[offset+6] = (byte) (0xff & (v >>> 48));    data[offset+7] = (byte) (0xff & (v >>> 56));  }