I want to create one custom element which has startEvent, extensionElements and flowable:eventType like image shown above.
Now I have one custom element using palette like below. But when I drag it into diagram, its icons will become startEvent default icon.
A metamodel is a higher-level model that defines the structure, rules, and constraints of other models within a certain domain. In other words, it’s a model that describes the characteristics and relationships that other models should have. Metamodels are often used in software engineering, system design, and various modeling disciplines to provide a framework for creating and understanding different types of models.