How to remove an element of a BPMN model using java API?

Hi, I’m trying to use Camunda API to manipulate my BPMN models, but I don’t find enough documentation and code samples to do what I want. The guid below is useful but I couldn’t use it to do the task.

I’m actually trying to implement a mutation generator for BPMN models, so that given a BPMN model, the tool should generate new models with changes (e.g. addition/removal of elements) to the original model.

Now I want to remove a random node within the given model but I don’t succeed. After the node is removed, the nodes before and after the deleted node need to be reconnected.

Here’s what I’ve got so far:

	public static void main(String[] args) {
		try {
		} catch (Exception e) {
			// TODO Auto-generated catch block
	private static void removeMiddleNode() {
		File f = new File("data/mutation/input/103082.bpmn");
		BpmnModelInstance modelInstance = Bpmn.readModelFromFile(f);		
		//this is not the right way. I use this to access the parent node to add the sequenceFlow to it but I think it needs to be added to the parent process instead. Not sure how to access it.
		Task task = modelInstance.getModelElementById("sourceNodeID");
		ModelElementInstance parentElement = task.getParentElement();
		//these are the nodes before and after the node to be deleted, but they need to be set based on the chosen node to be deleted
		FlowNode sourceNode = modelInstance.getModelElementById("sourceNodeID");
		FlowNode targetNode = modelInstance.getModelElementById("targetNodeID");
		//the code for deleting the node and its incoming and outgoing sequence flows should go here.
		//reconnect the nodes that are before and after the deletecd node
		createSequenceFlow(modelInstance, parentElement, sourceNode, targetNode);
		// write to file
		File file = new File("data/mutation/output/mutant.bpmn");
		Bpmn.writeModelToFile(file, modelInstance);
	  public static SequenceFlow createSequenceFlow(BpmnModelInstance modelInstance, ModelElementInstance parentElement, FlowNode from, FlowNode to) {
		  String identifier = from.getId() + "-" + to.getId();
		  SequenceFlow sequenceFlow = createElement(modelInstance, parentElement, identifier, SequenceFlow.class);
		  return sequenceFlow;
	  protected static  <T extends BpmnModelElementInstance> T createElement(BpmnModelInstance modelInstance, ModelElementInstance parentElement, String id, Class<T> elementClass) {
		  T element = modelInstance.newInstance(elementClass);
		  element.setAttributeValue("id", id, true);
		  return element;