code: public Apptentive.DateTime getTimeAtInstallForVersionCode(int versionCode) {
  		for (VersionHistoryItem item : versionHistoryItems) {
  			if (item.getVersionCode() == versionCode) {
  				return new Apptentive.DateTime(item.getTimestamp());
  			}
  		}
  		return new Apptentive.DateTime(Util.currentTimeSeconds());
  	}
docs: Returns the timestamp at the first install of the current versionCode of this app that Apptentive was aware of.