private static ContentPropertyKey buildKey(Class<?> clazz, Class<?> headClass, String fieldName) {
        return new ContentPropertyKey(clazz, headClass, fieldName);
    }
Calculate the configuration information for the class

@param dataMap
@param headClazz
@param fieldName
@return
fastexcel-core/src/main/java/cn/idev/excel/util/ClassUtils.java