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export class PseudoPromise<PayloadType = undefined> {  readonly promise: Promise<PayloadType>;
  constructor(promise: Promise<PayloadType>) {    this.promise = promise;  }
  then<MappedType>(    f: (_v: PayloadType) => MappedType  ): PseudoPromise<MappedType> {    return new PseudoPromise<MappedType>(this.promise.then(f));  }
  static all = <T extends (any | PseudoPromise<any>)[]>(    pps: T  ): PseudoPromise<    { [K in keyof T]: T[K] extends PseudoPromise<infer I> ? I : T[K] }  > => {    return new PseudoPromise(      Promise.all(pps.map((v) => (v instanceof PseudoPromise ? v.promise : v)))    ) as any;  };}