@staticmethod<EOL><INDENT>def get_run(session, dag_id, execution_date):<DEDENT>
qry = session.query(DagRun).filter(<EOL>DagRun.dag_id == dag_id,<EOL>DagRun.external_trigger == False, <EOL>DagRun.execution_date == execution_date,<EOL>)<EOL>return qry.first()<EOL>
:param dag_id: DAG ID
:type dag_id: unicode
:param execution_date: execution date
:type execution_date: datetime
:return: DagRun corresponding to the given dag_id and execution date
    if one exists. None otherwise.
:rtype: airflow.models.DagRun