/**
 * Thrown when waitForTransactionWithFallback times out.
 * lastError distinguishes network issues (present) from slow tx (null).
 */
export declare class TransactionWaitTimeoutError extends Error {
    name: string;
    txHash: string;
    timeoutMs: number;
    lastError: Error | null;
    constructor(txHash: string, timeoutMs: number, lastError: Error | null);
}