public Entry (int piece, PositionRange pieceRange, Path file, PositionRange fileRange) {
            if (piece < 0 | pieceRange.getLength() != fileRange.getLength()) {
                throw new IllegalArgumentException();
            }
            if (file == null) {
                throw new NullPointerException();
            }

            this.piece = piece;
            this.pieceRange = pieceRange;
            this.file = file;
            this.fileRange = fileRange;
        }