Interface PreviousHashStore

interface PreviousHashStore {
    getItem(
        address: Lowercase<string>,
    ): null | Lowercase<string> | Promise<null | Lowercase<string>>;
    removeItem(address: Lowercase<string>): void | Promise<void>;
    setItem(
        address: Lowercase<string>,
        previousHash: Lowercase<string>,
    ): void | Promise<void>;
}