public static <T> DiffResult<T> diff(@Nonnull SheetReader<T> a, @Nonnull SheetReader<T> b,
ReportGenerator reportGenerator) {
Collection<T> ca = a.read();
Collection<T> cb = b.read();
Collection<T> disjunction = CollectionUtils.disjunction(ca, cb);
Info<T> info = new ReportInfo<T>(new Files(a.getSheet().getFile().getAbsolutePath(), b.getSheet().getFile()
.getAbsolutePath()), new Sheets(a.getSheet().getNativeSheet().getSheetName(), b.getSheet().getNativeSheet()
.getSheetName()), new Collections<T>(ca, cb, disjunction));
ReportGenerator reporter;
if (reportGenerator != null) {
reporter = reportGenerator;