@Override
    public int hashCode() {
        return 0;
    }
@param injector Don't inject classes from other db modules, or it will create unwanted
                dependencies between modules. Intended for use with CrossModuleDbMigrationsModule
                only.
@return True if the migration was run, whether it migrated anything or not.
stroom-db-util/src/main/java/stroom/db/util/AbstractDataSourceProviderModule.java