@Override
        protected Integer doInBackgroundInternal(final Void[] params) {
            try (ContextLogger ignore = new ContextLogger(true, "LocalStorage: perform Migration from " + currentMigrateVersion + " to " + finalVersion)) {
                return doMigration();
            } catch (RuntimeException re) {
                Log.e("LocalStorage: Exception during Migration to v" + finalVersion + ", stays in v" + currentMigrateVersion, re);
                return currentMigrateVersion;
            }

        }
Returns the external public cgeo directory, something like <pre>/sdcard/cgeo</pre>.
It falls back to the internal cgeo directory if the external is not available.
main/src/main/java/cgeo/geocaching/storage/LocalStorage.java