final void cookie(Iterable<? extends Cookie> cookies) {
        //noinspection unchecked
        addCookies((Iterable<Cookie>) cookies, HttpHeaderNames.COOKIE, Cookie::toCookieHeader);
    }
Adds the specified {@code cookies} with {@link HttpHeaderNames#COOKIE}.
core/src/main/java/com/linecorp/armeria/common/HttpHeadersBase.java