public void migrate(InputStream fromSource, OutputStream toDest, IApimanLogger extraLogger) {
        this.logger = new DoubleLogger(logger, extraLogger);
        migrate(fromSource, toDest);
    }
Migrate the data export file (fromSource) from whatever version it
is to the latest apiman version format and write the result to a
file (toDest).
@param fromSource migration source
@param toDest migration destination
manager/api/migrator/src/main/java/io/apiman/manager/api/migrator/DataMigrator.java