question: 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 ) ; } }
target:  Expands the hash "spine" -- equivalent to increasing the number of buckets in a conventional hash table.