Escrow contract

Create Escrow (Source User)

The user send his NFT to Escorw contract with send message (which is basic function of cw721 base contract).

-Options

1.Set the expiration time for escrow.

2.Set the recipient for the NFT.

3.Set the price of NFT.

Accept the NFT (Recipient)

-Check if the sent money from recipeint to the escrow contract is the same as the amount of fund which the
source user set

-Validate the expiration time.

Withdraw NFT (Source User)

If the expiration is finished, the source user can withdraw his NFT.