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contracts...17_Enum.sol

pragma solidity 0.5.11;

contract Enum {
    enum Status {
        Pending,
        Shipped, 
        Accepted,
        Rejected,
        Canceled
    }

    Status public status;

    function ship() public {
        require(status == Status.Pending);
        status = Status.Shipped;
    }

    function acceptDelivery() public {
        require(status == Status.Shipped);
        status = Status.Accepted;
    }

    function recjectDelivery() public {
        require(status == Status.Shipped);
        status = Status.Rejected;
    }

    function cancelOrder() public {
        require(status == Status.Pending);
        status = Status.Canceled;
    }
}