slice! (LazyArray)

    # File lib/extlib/lazy_array.rb, line 115
      def slice!(*args)
        index, length = extract_slice_arguments(*args)

        if index >= 0 && lazy_possible?(@head, index + length)
          @head.slice!(*args)
        elsif index < 0 && lazy_possible?(@tail, index.abs - 1 + length)
          @tail.slice!(*args)
        else
          lazy_load
          @array.slice!(*args)
        end
      end