Solidity Events With Function Modifiers

constructor() public payable {
        seller = msg.sender;
        value = msg.value / 2;
        require((2 * value) == msg.value, "Value has to be even.");
    }

    modifier condition(bool _condition) {
        require(_condition);
        _;
    }

    modifier onlyBuyer() {
        require(
            msg.sender == buyer,
            "Only buyer can call this."
        );
        _;
    }

    modifier onlySeller() {
        require(
            msg.sender == seller,
            "Only seller can call this."
        );
        _;
    }

    modifier inState(State _state) {
        require(
            state == _state,
            "Invalid state."
        );
        _;
    }

    event Aborted();
    event PurchaseConfirmed();
    event ItemReceived();