public static MultiValueMap asMultiValueMap(final String key, final Object value) {
        return org.springframework.util.CollectionUtils.toMultiValueMap(wrap(key, value));
    }
As multi value map.

@param key   the key
@param value the value
@return the multi value map
core/cas-server-core-util-api/src/main/java/org/apereo/cas/util/CollectionUtils.java