import { SporeExtension } from '../types';
/**
 * A core extension of Spore NFT, to allow a spore cell to be indestructible on-chain.
 *
 * When setting a spore cell to be "immortal", the spore cell will be indestructible,
 * it cannot be melted, therefore the cell can be lived on the blockchain forever.
 */
export declare function useImmortal(): SporeExtension;
export declare function isImmortalParameterValid(immortal: unknown): boolean;
export declare function getImmortalParameter(): void;