spring bean explicit singleton scope declaration

In below spring bean declaration, I wonder why do we need explicit scope="singleton". Isn't it redundant?

<bean class="com.foo.blah.JerseyJacksonConfigFactory" factory-method="getProvider" scope="singleton"/>

public class JerseyJacksonConfigFactory {
    public static ClientConfig getConfig() {
        JacksonJsonProvider jsonProvider = getProvider();
        DefaultClientConfig config = new DefaultClientConfig();
        config.getSingletons().add(jsonProvider);
        return config;
    }

    public static JacksonJsonProvider getProvider() {
        ObjectMapper mapper = getObjectMapper();
        JacksonJsonProvider jsonProvider = new JacksonJsonProvider();
        jsonProvider.setMapper(mapper);
        return jsonProvider;
    }

    public static ObjectMapper getObjectMapper() {
        return new ObjectMapper()
                    .configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false)
                    .setPropertyNamingStrategy(PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES)
                    .setSerializationInclusion(JsonSerialize.Inclusion.NON_EMPTY);
    }
}