public static String quoteIfNeeded(String etag) {
        if (etag != null && (etag.isEmpty() || etag.charAt(0) != '"')) {
            return "\"" + etag + "\"";
        }

        return etag;
    }
Constructs etag header instance.

@param ifMatch HTTP header
@param ifNoneMatch HTTP header
storage/src/main/java/com/epam/aidial/core/storage/util/EtagHeader.java