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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 export_lane_set(process, lane_set, plane_element):
 """ Creates 'laneSet' element for exported BPMN XML file. :param process: an XML element ('process'), from exported BPMN 2.0 document, :param lane_set: dictionary with exported 'laneSet' element attributes and child elements, :param plane_element: XML object, representing 'plane' element of exported BPMN 2.0 XML. """

        lane_set_xml = eTree.SubElement(process, consts.Consts.lane_set)
        for key, value in lane_set[consts.Consts.lanes].items():
            BpmnDiagramGraphExport.export_lane(lane_set_xml, key, value, plane_element)