public void pad(int byte_size){
  for (int i=0; i < byte_size; i++)   bb.put(--space,(byte)0);
}

public void pad ( int byte_size ) { for ( int i = 0 ; i < byte_size ; i ++ ) bb . put ( -- space , ( byte ) 0 ) ; }
add zero valued bytes to prepare a new entry to be added .
