private static ApplicationId fromIdString(String idString, String splitCharacter) {
        String[] parts = idString.split(Pattern.quote(splitCharacter));
        if (parts.length != 3)
            throw new IllegalArgumentException("Application ids must be on the form tenant" +
                                                       splitCharacter + "application" + splitCharacter + "instance, but was " + idString);
        return from(parts[0], parts[1], parts[2]);
    }
A complete, immutable identification of an application instance.

@author Ulf Lilleengen
@author vegard
@author bratseth
config-provisioning/src/main/java/com/yahoo/config/provision/ApplicationId.java