code: public static byte toByte(TypeOfAddress toa) {
          byte b = 0;
          if (toa.getTon() != null) {
              b |= ( toa.getTon().toInt() << 0 );
          }
          if (toa.getNpi() != null) {
              b |= ( toa.getNpi().toInt() << 4 );
          }
          b |= ( 1 << 7 );
          return b;
      }
docs: To a GSM-encoded type of address byte.
  @return The byte representing a type of address