code: public static byte[] longToRegisters(long v) {
          byte[] registers = new byte[8];
          registers[0] = (byte)(0xff & (v >> 56));
          registers[1] = (byte)(0xff & (v >> 48));
          registers[2] = (byte)(0xff & (v >> 40));
          registers[3] = (byte)(0xff & (v >> 32));
          registers[4] = (byte)(0xff & (v >> 24));
          registers[5] = (byte)(0xff & (v >> 16));
          registers[6] = (byte)(0xff & (v >> 8));
          registers[7] = (byte)(0xff & v);
          return registers;
      }
docs: Converts a long value to a byte[8].
  
  @param v the value to be converted.
  
  @return a byte[8] containing the long value.