流程环节

引用：app.flow.flowentity

流程环节(Class):FlowActivity

getActivity：获取环节标识

getActivityname：获取环节名称

getBeforeActivity(self):  # 获取前序环节

返回：list<FlowActivity>

getAfterActivity(self):  # 获取后续环节

返回：list<FlowActivity>

getTaskAfterActivity(self, flowID, taskID, sData1):  # 获取流程后续环节