public boolean isConcrete() {
        return !isWildcardType() && !isWildcardSubtype();
    }
@author James Chen
@implNote The class drop the media type parameters just because we don't need it currently
@see <a href="https://www.iana.org/assignments/media-types/media-types.xhtml">Media Types</a>
turms-server-common/src/main/java/im/turms/server/common/access/admin/web/MediaType.java