question: @ SuppressWarnings ( "unchecked" ) private static HeapOperand < Object > [ ] extendHArray ( HeapOperand < Object > [ ] H ) { HeapOperand < Object > [ ] res ; if ( H == null ) { res = new HeapOperand [ 1 ] ; } else { res = new HeapOperand [ H . length + 1 ] ; for ( int i = 0 ; i < H . length ; ++ i ) { res [ i + 1 ] = H [ i ] ; } } return res ; }
target:  Returns a copy of H with an additional free slot at position 0