code: def import_lane_set_element(process_attributes, lane_set_element, plane_element):
          
          lane_set_id = lane_set_element.getAttribute(consts.Consts.id)
          lanes_attr = {}
          for element in utils.BpmnImportUtils.iterate_elements(lane_set_element):
              if element.nodeType != element.TEXT_NODE:
                  tag_name = utils.BpmnImportUtils.remove_namespace_from_tag_name(element.tagName)
                  if tag_name == consts.Consts.lane:
                      lane = element
                      lane_id = lane.getAttribute(consts.Consts.id)
                      lane_attr = BpmnDiagramGraphImport.import_lane_element(lane, plane_element)
                      lanes_attr[lane_id] = lane_attr
  
          lane_set_attr = {consts.Consts.id: lane_set_id, consts.Consts.lanes: lanes_attr}
          process_attributes[consts.Consts.lane_set] = lane_set_attr
docs: Method for importing 'laneSet' element from diagram file.
  
          :param process_attributes: dictionary that holds attribute values of 'process' element, which is parent of
              imported flow node,
          :param lane_set_element: XML document element,
          :param plane_element: object representing a BPMN XML 'plane' element.