import type { LanguageModelV4StreamPart } from "@ai-sdk/provider";
import type { HealthTransition } from "./health-store.js";
import { FallbackPumpContext } from "./stream-pump-context.js";
import type { FailureClassification, RouterOrderingToken } from "./types.js";
export declare abstract class FallbackPumpState extends FallbackPumpContext {
    run(): Promise<void>;
    cancel(reason: unknown): void;
    resume(): void;
    failUnexpected(error: unknown): void;
    protected safeEnqueue(part: LanguageModelV4StreamPart): void;
    protected safeClose(): void;
    protected safeError(error: unknown): void;
    protected flushPrelude(): void;
    protected emitOnError(error: unknown, idx: number, willRetry: boolean): void;
    protected recordCandidateFailure(idx: number, classification: FailureClassification): HealthTransition | undefined;
    protected recordCandidateSuccess(idx: number): HealthTransition | undefined;
    protected nextAttemptOrderingToken(): RouterOrderingToken;
}