private static String getCauseMessage(Throwable e) {
        // Don't pull back more than one layer since that context might be useful.
        return e.getCause() != null ? e.getCause().getMessage() : e.getMessage();
    }
The default implementations use to convert Nodes into Objects through a {@link NodeMapper}.
smithy-model/src/main/java/software/amazon/smithy/model/node/DefaultNodeDeserializers.java