How can i complete more than one user task single rest request?

my scenario, i have a Error Task (user task) and possible errors handling this task. Every Error task be different process instance. we need single rest call and multiple Task complete. any idea?

this solotion not good

for(taskId in tasks){
     _client.CompleteUserTask(taskId,variables)
}

because, may to many rest call create

best regard.