public byte[] toBytes(){
  byte[] returnBytes=new byte[bytesLength];
  System.arraycopy(bytes,0,returnBytes,0,bytesLength);
  return returnBytes;
}

public byte [ ] toBytes ( ) { byte [ ] returnBytes = new byte [ bytesLength ] ; System . arraycopy ( bytes , 0 , returnBytes , 0 , bytesLength ) ; return returnBytes ; }
get the composed bytes of pdu .
