How to pass data to downstream task.branch task using TaskFlow Syntax?

[rodigu]

I am creating a DAG, in which I want to include a branching task.
The branching task will select tasks that should receive data through their parameters.

Here is a simplification:

@dag
def branching_dag():
    @task.branch(task_id='branching_task')
    def choose_task(do_a: bool):
        if do_a:
            return "do_a"
        return "do_b"
    
    @task
    def a(text: str):
        print(text)
    
    def b(text: str):
        print(f'{text} but in b')
    
    choose_task(True)

How can I pass data to a or b?

I have read on Airflow XComs, but the documentation seems a little unclear. Is task_instance a variable that is always available? How should I import or access it using the TaskFlow API?