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**Description**

Related to the discussion here: https://github.com/apache/airflow/pull/8553#discussion_r416136954

Allow user to define expected terminal state. e.g. `JOB_STATE_CANCELLED` could be not treated as failure but expected terminal state.


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"""
    Starts Dataflow SQL query.
    .. seealso::
        For more information on how to use this operator, take a look at the guide:
        :ref:`howto/operator:DataflowStartSqlJobOperator`
    .. warning::
        This operator requires ``gcloud`` command (Google Cloud SDK) must be installed on the Airflow worker
        <https://cloud.google.com/sdk/docs/install>`__
    :param job_name: The unique name to assign to the Cloud Dataflow job.
    :param query: The SQL query to execute.
    :param options: Job parameters to be executed. It can be a dictionary with the following keys.
        For more information, look at: