private static void appendValue(StringBuilder builder, String key, String value, boolean addComma) {
        builder.append(key);
        builder.append("=\"");
        encodeComponent(builder, value);
        if (addComma) {
            builder.append("\",");
        } else {
            builder.append('"');
        }
    }
Returns the string that is sent as the value of the {@link HttpHeaderNames#AUTHORIZATION} header.
core/src/main/java/com/linecorp/armeria/common/auth/OAuth1aToken.java