code: def export_node(bpmn_graph, export_elements, node, nodes_classification, order=0, prefix="", condition="", who="",
                      add_join=False):
          
          node_type = node[1][consts.Consts.type]
          if node_type == consts.Consts.start_event:
              return BpmnDiagramGraphCsvExport.export_start_event(bpmn_graph, export_elements, node, nodes_classification,
                                                                  order=order, prefix=prefix, condition=condition,
                                                                  who=who)
          elif node_type == consts.Consts.end_event:
              return BpmnDiagramGraphCsvExport.export_end_event(export_elements, node, order=order, prefix=prefix,
                                                                condition=condition, who=who)
          else:
              return BpmnDiagramGraphCsvExport.export_element(bpmn_graph, export_elements, node, nodes_classification,
                                                              order=order, prefix=prefix, condition=condition, who=who,
                                                              add_join=add_join)
docs: General method for node exporting
  
          :param bpmn_graph: an instance of BpmnDiagramGraph class,
          :param export_elements: a dictionary object. The key is a node ID, value is a dictionary of parameters that
                 will be used in exported CSV document,
          :param node: networkx.Node object,
          :param nodes_classification: dictionary of classification labels. Key - node id. Value - a list of labels,
          :param order: the order param of exported node,
          :param prefix: the prefix of exported node - if the task appears after some gateway, the prefix will identify
                 the branch
          :param condition: the condition param of exported node,
          :param who: the condition param of exported node,
          :param add_join: boolean flag. Used to indicate if "Join" element should be added to CSV.
          :return: None or the next node object if the exported node was a gateway join.