code: protected static List<JsonLookupResult> getBpmnProcessModelChildShapesPropertyValues(JsonNode editorJsonNode, String propertyName, List<String> allowedStencilTypes) {
      List<JsonLookupResult> result = new ArrayList<JsonLookupResult>();
      internalGetBpmnProcessChildShapePropertyValues(editorJsonNode, propertyName, allowedStencilTypes, result);
      return result;
    }
docs: Usable for BPMN 2.0 editor json: traverses all child shapes (also nested), goes into
  the properties and sees if there is a matching property in the
  'properties' of the childshape and returns those in a list.
  
  Returns a map with said json nodes, with the key the name of the childshape.