private void growSpine(){
  spine=new int[(spine.length << 1) + 1];
  threshold=(int)(spine.length * loadFactor);
  Arrays.fill(spine,-1);
  for (int i=0; i < size; i++) {
    insert(objs[i],i);
  }
}

private void growSpine ( ) { spine = new int [ ( spine . length << 1 ) + 1 ] ; threshold = ( int ) ( spine . length * loadFactor ) ; Arrays . fill ( spine , - 1 ) ; for ( int i = 0 ; i < size ; i ++ ) { insert ( objs [ i ] , i ) ; } }
expands the hash " spine " - - equivalent to increasing the number of buckets in a conventional hash table .
