{
// some event data;
 "extendedProperties": {
  "shared": {
   "cases_1": "1",
   "cases_2": "2"
  }
 }
}

{
 "extendedProperties": {
  "shared": {
   "cases_2": "2"
  }
 }
}

{
 "extendedProperties": {
  "shared": {
   "cases_1": null,
   "cases_2": "2"
  }
 }
}