[TestMethod()]
public void TestMultiInit()
    {
        var Client2 = new cpEasyPost("123");
        var Client = new cpEasyPost("123456qq785412");

        var Shipment = Client.CreateShipment(
             new EasyPost.Address
             {
                 street1 = "417 MONTGOMERY ST",
                 street2 = "FLOOR 5",
                 city = "SAN FRANCISCO",
                 state = "CA",
                 zip = "94104",
                 country = "US",
                 company = "EasyPost"
             },
             new EasyPost.Address
             {
                 street1 = "417 MONTGOMERY ST",
                 street2 = "FLOOR 5",
                 city = "SAN FRANCISCO",
                 state = "CA",
                 zip = "94104",
                 country = "US",
                 company = "EasyPost"
             },
             new EasyPost.Parcel
             {
                 length = 20.2,
                 width = 10.9,
                 height = 5,
                 weight = 65.9
             });

        var Shipment2 = Client2.CreateShipment(
             new EasyPost.Address
             {
                 street1 = "417 MONTGOMERY ST",
                 street2 = "FLOOR 5",
                 city = "SAN FRANCISCO",
                 state = "CA",
                 zip = "94104",
                 country = "US",
                 company = "EasyPost"
             },
             new EasyPost.Address
             {
                 street1 = "417 MONTGOMERY ST",
                 street2 = "FLOOR 5",
                 city = "SAN FRANCISCO",
                 state = "CA",
                 zip = "94104",
                 country = "US",
                 company = "EasyPost"
             },
             new EasyPost.Parcel
             {
                 length = 20.2,
                 width = 10.9,
                 height = 5,
                 weight = 65.9
             });


    }

public cpEasyPost(string secretKey)
    {
        SecretKey = secretKey;
        //Original way of init Client
        //ClientManager.SetCurrent(SecretKey);

        //Create ClientManager
        ClientManager.SetCurrent(() => new Client(new ClientConfiguration(SecretKey)));
    }

public Shipment CreateShipment(Address AddressFrom, Address AddressTo, Parcel Parcel, CustomsInfo customs = null, string CustomReference = "", double? InsauranceAmount = null)
    {
        //Validate Adress
        var isValidFrom = ValidateAddress(AddressFrom);
        var isValidTo = ValidateAddress(AddressFrom);

        if (!isValidFrom.isSuccess)
            throw new Exception("Address From is not Valid");

        if (!isValidTo.isSuccess)
            throw new Exception("Address To is not Valid");

        //Validate Pacrcel
        var isValidParcel = ValidateParcel(Parcel);

        if (!isValidFrom.isSuccess)
            throw new Exception("Parcel is not Valid");

        //Create Shipment
        Shipment shipment = new Shipment()
        {
            reference = CustomReference,
            to_address = AddressTo,
            from_address = AddressFrom,
            parcel = Parcel,
            customs_info = customs
        };

        //ClientManager.SetCurrent(SecretKey); **
        shipment.Create();

        //Add Insurance
        if (InsauranceAmount != null)
            shipment.Insure(InsauranceAmount.Value);

        return shipment;

    }