protected static <T extends Element> IdManager<T> selectIdManager(final Configuration config, final String configKey, final Class<T> clazz) {
        final String vertexIdManagerConfigValue = config.getString(configKey, DefaultIdManager.ANY.name());
        try {
            return DefaultIdManager.valueOf(vertexIdManagerConfigValue);
        } catch (IllegalArgumentException iae) {
            try {
                return (IdManager) Class.forName(vertexIdManagerConfigValue).newInstance();
            } catch (Exception ex) {
                throw new IllegalStateException(String.format("Could not configure TinkerGraph %s id manager with %s", clazz.getSimpleName(), vertexIdManagerConfigValue));
            }
        }
    }
Construct an {@link IdManager} from the TinkerGraph {@code Configuration}.
tinkergraph-gremlin/src/main/java/org/apache/tinkerpop/gremlin/tinkergraph/structure/AbstractTinkerGraph.java