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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def stop_pipeline(url, pipeline_id, auth, verify_ssl):
 """Stop a running pipeline. The API waits for the pipeline to be 'STOPPED' before returning. Args: url (str):
 the host url in the form 'http://host:port/'. pipeline_id (str):
 the ID of of the exported pipeline. auth (tuple):
 a tuple of username, and password. verify_ssl (bool):
 whether to verify ssl certificates Returns: dict: the response json """


    stop_result = requests.post(url + '/' + pipeline_id + '/stop', headers=X_REQ_BY, auth=auth, verify=verify_ssl)
    stop_result.raise_for_status()

    logging.info("Pipeline stop requested.")

    poll_pipeline_status(STATUS_STOPPED, url, pipeline_id, auth, verify_ssl)

    logging.info('Pipeline stopped.')
    return stop_result.json()