public static String decodePathParam(String pathParam) {
        if (pathParam.indexOf('%') < 0) {
            // No need to decode because it's not percent-encoded
            return pathParam;
        }

        // Decode percent-encoded characters.
        return slowDecodePath(pathParam, true);
    }
Decodes a single percent-encoded path parameter.
core/src/main/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtil.java