import type { LanguageModelV4StreamPart } from "@ai-sdk/provider";
export declare class StreamLifecycleValidator {
    private finished;
    private readonly open;
    private readonly pendingToolCalls;
    private readonly seenToolCalls;
    private responseMetadataSeen;
    private streamStarted;
    validate(part: LanguageModelV4StreamPart): void;
    private assertTrackingCapacity;
    private validateSpecialPart;
}