我目前正在阅读使用Prisma的Nest.js应用程序的文档。根据文档，我创建了以下服务。

import { INestApplication, OnModuleInit } from "@nestjs/common";
import { PrismaClient } from "@prisma/client";

export class PrismaService extends PrismaClient implements OnModuleInit {
  async onModuleInit() {
    console.log('onModuleInit PrismaService')
    await this.$connect();
  }

  async enableShutdownHooks(app: INestApplication){
    this.$on('beforeExit', async () => {
      console.log('PrismaService enableShutdownHooks beforeExit')
      await app.close();
    });
  }
}

文档描述了以下各项的使用。

import { Module } from '@nestjs/common';
import { Prisma } from '@prisma/client';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { CsvParsersModule } from './csv-parsers/csv-parsers.module';
import { PrismaModule } from './prisma/prisma.module';
import { PrismaService } from './prisma/prisma.service';

@Module({
  imports: [CsvParsersModule],
  controllers: [AppController],
  providers: [AppService, PrismaService]
})
export class AppModule {}

但是，当服务在其他地方注册时，此类代码将导致onModuleInit被重复调用。

import { Global, Module } from '@nestjs/common';
import { CsvParsersService } from './csv-parsers.service';
import { CsvParsersController } from './csv-parsers.controller';
import { PrismaService } from 'src/prisma/prisma.service';

@Module({
  controllers: [CsvParsersController],
  providers: [CsvParsersService, PrismaService],
  exports: [CsvParsersService]
})
export class CsvParsersModule {}

[Nest] 78737  - 2022/07/21 8:05:23     LOG [NestFactory] Starting Nest application...
[Nest] 78737  - 2022/07/21 8:05:23     LOG [InstanceLoader] AppModule dependencies initialized +25ms
[Nest] 78737  - 2022/07/21 8:05:23     LOG [InstanceLoader] CsvParsersModule dependencies initialized +0ms
[Nest] 78737  - 2022/07/21 8:05:23     LOG [RoutesResolver] AppController {/}: +8ms
[Nest] 78737  - 2022/07/21 8:05:23     LOG [RouterExplorer] Mapped {/, GET} route +1ms
[Nest] 78737  - 2022/07/21 8:05:23     LOG [RoutesResolver] CsvParsersController {/csv-parsers}: +0ms
[Nest] 78737  - 2022/07/21 8:05:23     LOG [RouterExplorer] Mapped {/csv-parsers, POST} route +0ms
onModuleInit PrismaService
onModuleInit PrismaService
[Nest] 78737  - 2022/07/21 8:05:23     LOG [NestApplication] Nest application successfully started +51ms

我认为最好的方法是onModuleInit只被调用一次。这应该如何解决？