/**
 * @hidden
 */
export declare function spawnError(errorMessageFormat: string, ...errorMessageArgs: ReadonlyArray<unknown>): Error;
/**
 * An alternative to facebook's invariant that's safe to use with base data
 *
 * @hidden
 */
export declare function invariant(condition: unknown, errorMessageFormat: string, ...errorMessageArgs: Array<unknown>): asserts condition;
/**
 * @internal
 */
export declare function spawnUnknownSwitchCaseError(valueDescription: string, providedValue: never, key: string): Error;
/**
 * @internal
 */
export declare function spawnAbstractMethodError(): Error;