//Real Example============================
                      export type ProductType = {
                        _id: string;
                        pid: string;
                        name: string;
                        slug: string;
                        category: string;
                        image: string;
                        brand: string;
                        price: number;
                        countInStock: number;
                        rating: number;
                        reviews: number;
                        description: string;
                      };

                      export type State = {
                        products: ProductType[];
                        loading: boolean;
                        error: string;
                      };

                      export type Action =
                        | { type: 'FETCH_REQUEST' }
                        | { type: 'FETCH_SUCCESS'; payload: ProductType[] }
                        | { type: 'FETCH_FAIL'; payload: string };

                      export const initialState: State = {
                        products: [],
                        loading: true,
                        error: '',
                      };

                    //Cart Type ===========================
                      export type CartItemType = {
                        image: string | undefined;
                        slug: string;
                        quantity: number;
                        countInStock: number;
                        price: number;
                        _id: string;
                        pid: string;
                        name: string;
                      };

                      export type ShippingAddressType = {
                        fullname: string;
                        address: string;
                        city: string;
                        country: string;
                        pincode: string;
                      };

                      export type CartType = {
                        cartItems: CartItemType[];
                        shippingAddress: ShippingAddressType;
                        paymentMethod: string;
                        itemsPrice: number;
                        shippingCharges: number;
                        taxCharges: number;
                        totalPrice: number;
                      };

                      export type ActionType = | { type: 'SWITCH_MODE' } | { type: 'CART_ADD_ITEM'; payload: CartItemType };

                      export type AppStateType = { mode: string; cart: CartType; };