public BitsSlice(Bits parent, ReaderSlice slice) {this.parent = parent;this.start = slice.start;this.length = slice.length;assert length >= 0: "length=" + length;}

public BitsSlice(IBits parent, ReaderSlice slice){this.parent = parent;this.start = slice.Start;this.length = slice.Length;Debug.Assert(length >= 0, "length=" + length);}
