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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 _update_workflow_definition(pb_config: dict):
 """Update the PB configuration workflow definition. Args: pb_config (dict):
 PB configuration dictionary Raises: RunTimeError, if the workflow definition (id, version) specified in the sbi_config is not known. """

        known_workflows = get_workflows()
        workflow_id = pb_config['workflow']['id']
        workflow_version = pb_config['workflow']['version']
        if workflow_id not in known_workflows or \
           workflow_version not in known_workflows[workflow_id]:
            raise RuntimeError("Unknown workflow definition: {}:{}"
                               .format(workflow_id, workflow_version))
        workflow = get_workflow(workflow_id, workflow_version)
        for stage in workflow['stages']:
            stage['status'] = 'none'
        pb_config['workflow_parameters'] = pb_config['workflow']['parameters']
        pb_config['workflow_id'] = pb_config['workflow']['id']
        pb_config['workflow_version'] = pb_config['workflow']['version']
        pb_config['workflow_stages'] = workflow['stages']
        pb_config.pop('workflow', None)