writer.key("columnModel"); project.columnModel.write(writer, options);
writer.key("recordModel"); project.recordModel.write(writer, options);
writer.key("overlayModels"); writer.object();
for (String modelName : project.overlayModels.keySet()) {
OverlayModel overlayModel = project.overlayModels.get(modelName);
if (overlayModel != null) {
writer.key(modelName);
project.overlayModels.get(modelName).write(writer, options);
}