public void RegisterShareTest()
        {
            // Arrange
            var shareRepositoryMock = Substitute.For <ISharesRepository>();

            var sut = new SharesService(shareRepositoryMock);

            ShareRegistrationData share = new ShareRegistrationData
            {
                ShareType  = "Toyota",
                SharePrice = (decimal)6021023
            };

            // Act
            sut.RegisterShare(share);

            // Asserts
            shareRepositoryMock.Received(1).Insert(Arg.Is <Share>(x => x.ShareType == share.ShareType && x.Price == share.SharePrice));
        }