default String toQueryString() {
        try (TemporaryThreadLocals tempThreadLocals = TemporaryThreadLocals.acquire()) {
            final StringBuilder buf = tempThreadLocals.stringBuilder();
            return appendQueryString(buf).toString();
        }
    }
Encodes all parameter entries into a query string, as defined in
<a href="https://www.w3.org/TR/2014/REC-html5-20141028/forms.html#url-encoded-form-data">4.10.22.6,
HTML5 W3C Recommendation</a>.

@return the encoded query string.
core/src/main/java/com/linecorp/armeria/common/QueryParamGetters.java