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"""Example DAG demonstrating the usage of the XComArgs."""
import logging

from airflow import DAG
from airflow.operators.python import PythonOperator, get_current_context, task
from airflow.utils.dates import days_ago

log = logging.getLogger(__name__)


def generate_value():
    """Dummy function"""
    return "Bring me a shrubbery!"


@task
def print_value(value):
    """Dummy function"""
    ctx = get_current_context()
    log.info("The knights of Ni say: %s (at %s)", value, ctx['ts'])


with DAG(
    dag_id='example_xcom_args',
    default_args={'owner': 'airflow'},
    start_date=days_ago(2),
    schedule_interval=None,
    tags=['example']
) as dag:
    task1 = PythonOperator(
        task_id='generate_value',
        python_callable=generate_value,
    )

    print_value(task1.output)
