rest-assured/src/main/java/io/restassured/RestAssured.java
public static void objectMapper(ObjectMapper objectMapper) {
        Validate.notNull(objectMapper, "Default object mapper cannot be null");
        config = config().objectMapperConfig(ObjectMapperConfig.objectMapperConfig().defaultObjectMapper(objectMapper));
    }
public static void objectMapper(ObjectMapper objectMapper) {
        Validate.notNull(objectMapper, "Default object mapper cannot be null");
        config = config().objectMapperConfig(ObjectMapperConfig.objectMapperConfig().defaultObjectMapper(objectMapper));
    }
Set a object mapper that'll be used when serializing and deserializing Java objects to and from it's
document representation (XML, JSON etc).

@param objectMapper The object mapper to use.