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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 append_underlying_workflow_describe(globalworkflow_desc):
 """ Adds the "workflowDescribe" field to the config for each region of the global workflow. The value is the description of an underlying workflow in that region. """

    if not globalworkflow_desc or \
            globalworkflow_desc['class'] != 'globalworkflow' or \
            not 'regionalOptions' in globalworkflow_desc:
        return globalworkflow_desc

    for region, config in globalworkflow_desc['regionalOptions'].items():
        workflow_id = config['workflow']
        workflow_desc = dxpy.api.workflow_describe(workflow_id)
        globalworkflow_desc['regionalOptions'][region]['workflowDescribe'] = workflow_desc
    return globalworkflow_desc