code: def add_instance(self, instance):
          
  
          assert isinstance(instance, dict)
  
          item = defaults["common"].copy()
          item.update(defaults["instance"])
  
          item.update(instance["data"])
          item.update(instance)
  
          item["itemType"] = "instance"
          item["isToggled"] = instance["data"].get("publish", True)
          item["hasCompatible"] = True
          item["category"] = item["category"] or item["family"]
  
          self.add_section(item["category"])
  
          # Visualised in Perspective
          families = [instance["data"]["family"]]
          families.extend(instance["data"].get("families", []))
          item["familiesConcatenated"] += ", ".join(families)
  
          item = self.add_item(item)
          self.instances.append(item)
docs: Append `instance` to model
  
          Arguments:
              instance (dict): Serialised instance
  
          Schema:
              instance.json