def add_task_to_diagram(self, process_id, task_name="<STR_LIT>", node_id=None):
return self.add_flow_node_to_diagram(process_id, consts.Consts.task, task_name, node_id)<EOL>
Adds a Task element to BPMN diagram.
User-defined attributes:

- name


:param process_id: string object. ID of parent process,
:param task_name: string object. Name of task,
:param node_id: string object. ID of node. Default value - None.
:return: a tuple, where first value is task ID, second a reference to created object.