import { ExecutionContext } from '@nestjs/common';
import { EventEmitter } from 'stream';
export type OtelNestjsEventListener = (traceId?: string, error?: Error, result?: unknown, context?: ExecutionContext) => void;
export declare class OtelNestjsEvent {
    private readonly eventEmitter;
    constructor(eventEmitter: EventEmitter);
    on(event: 'spanStartFailed', listener: (error: unknown) => void): void;
    on(event: 'spanFinished', listener: (traceId: string) => void): void;
    on(event: 'spanStarted', listener: (traceId: string) => void): void;
    on(event: 'spanFinishError', listener: (traceId: string, error: unknown) => void): void;
    on(event: string, listener: Parameters<EventEmitter['on']>[1]): void;
}