private int[] joinMap(int[] a,int[] b){
  if (a == null) {
    return b;
  }
  if (b == null) {
    return a;
  }
  int[] result=new int[a.length + b.length];
  System.arraycopy(a,0,result,0,a.length);
  System.arraycopy(b,0,result,a.length,b.length);
  return result;
}

private int [ ] joinMap ( int [ ] a , int [ ] b ) { if ( a == null ) { return b ; } if ( b == null ) { return a ; } int [ ] result = new int [ a . length + b . length ] ; System . arraycopy ( a , 0 , result , 0 , a . length ) ; System . arraycopy ( b , 0 , result , a . length , b . length ) ; return result ; }
joins two map arrays ( int [ ] ) together .
