function deposit(address listingAddress, uint _amount) external {
        Listing storage listing = listings[listingAddress];

        require(listing.owner == msg.sender, "Sender is not owner of Listing");

        listing.unstakedDeposit += _amount;
        require(token.transferFrom(msg.sender, this, _amount), "Token transfer failed");

        emit _Deposit(listingAddress, _amount, listing.unstakedDeposit, msg.sender);
    }