public Builder vespaVersionToBuildFirst(String version) {
            Optional<Version> v = Optional.empty();
            if (version != null && !version.isEmpty()) {
                v = Optional.of(Version.fromString(version));
            }
            return vespaVersionToBuildFirst(v);
        }
Parameters for preparing an application. Immutable.

@author Ulf Lilleengen
configserver/src/main/java/com/yahoo/vespa/config/server/session/PrepareParams.java