在Kotlin Lambda中调用RxJava Single

import io.reactivex.Single
import io.reactivex.schedulers.Schedulers

fun main() {
    val single = Single.create<String> { emitter ->
        // 异步操作，例如网络请求或数据库查询
        val result = fetchDataFromServer()
        emitter.onSuccess(result)
    }

    single.subscribeOn(Schedulers.io())
        .observeOn(Schedulers.single())
        .subscribe(
            { result ->
                // 处理成功结果
                println("Success: $result")
            },
            { error ->
                // 处理错误情况
                println("Error: ${error.message}")
            }
        )
}

fun fetchDataFromServer(): String {
    // 模拟网络请求
    Thread.sleep(1000)
    return "Data from server"
}