private static StringBuilder getDiff(PackageSet actual, PackageSet expected) {
        StringBuilder sb = new StringBuilder();

        var onlyInActual = actual.minus(expected);
        if (! onlyInActual.packages().isEmpty()) {
            sb.append("\nexportPackages.properties contained ")
                    .append(onlyInActual.packages.size())
                    .append(" unexpected packages:\n")
                    .append(onlyInActual);
        }

        var onlyInExpected = expected.minus(actual);
        if (! onlyInExpected.packages.isEmpty()) {
            sb.append("\nexportPackages.properties did not contain ")
                    .append(onlyInExpected.packages.size())
                    .append(" expected packages:\n")
                    .append(onlyInExpected);
        }
        return sb;
    }
Integration tests for {@link ExportPackages}.

@author gjoranv
jdisc_core/src/test/java/com/yahoo/jdisc/core/ExportPackagesIT.java