public async Task StreamWithoutEvents_Exists_ShouldReturnFalse()
        {
            //Arrange
            int id  = 42;
            var sut = new ConfigurationStub <TestState>()
                      .WithDefaultSetup()
                      .GetNewSUT <int>();

            //Act
            var exists = await sut.Contains(id);

            //Assert
            exists.Should().BeFalse();
        }
        public async Task StreamWithOneEvent_ExistsWithDifferentId_ShouldReturnFalse()
        {
            //Arrange
            int    idWithEvent = 42;
            object @event      = new object();
            var    sut         = new ConfigurationStub <TestState>()
                                 .WithDefaultSetup()
                                 .GetNewSUT <int>()
                                 .WithEventInStream(@event, idWithEvent);

            //Act
            var exists = await sut.Contains(idWithEvent + 1);

            //Assert
            exists.Should().BeFalse();
        }