private String makeJson(String s, WorkflowInstance workflowInstance) {
s = s.replace("%t", checkIfNull(workflowInstance.getTitle(), "Title"));
s = s.replace("%i", String.valueOf(workflowInstance.getId()));
s = s.replace("%s", String.valueOf(workflowInstance.getState()));
s = s.replace("%o", String.valueOf(workflowInstance.getCurrentOperation().getId()));
s = s.replace("%I", checkIfNull(workflowInstance.getMediaPackage().getIdentifier(), "Mediapackage-ID"));
s = s.replace("%T", checkIfNull(workflowInstance.getMediaPackage().getTitle(), "Mediapackage-Title"));
s = s.replace("%c", checkIfNull(workflowInstance.getMediaPackage().getContributors(), "Contributors"));
s = s.replace("%C", checkIfNull(workflowInstance.getMediaPackage().getCreators(), "Creators"));
s = s.replace("%D", checkIfNull(workflowInstance.getMediaPackage().getDate(), "Date"));
s = s.replace("%d", checkIfNull(workflowInstance.getMediaPackage().getDuration(), "Duration"));
s = s.replace("%l", checkIfNull(workflowInstance.getMediaPackage().getLanguage(), "Language"));
s = s.replace("%L", checkIfNull(workflowInstance.getMediaPackage().getLicense(), "License"));
s = s.replace("%S", checkIfNull(workflowInstance.getMediaPackage().getSeriesTitle(), "Series-Title"));
JsonObject json = new JsonObject();
json.addProperty("text", s);
return gson.toJson(json);
}