public void FindReceiver_GivenThereIsNoReceiver_ReturnsNull()
        {
            // Act
            var receiver = capacityZeroPipe.FindReceiver(capacityZeroPipe.Inlet);

            // Assert
            receiver.Should().BeNull();
        }
        public void FindReceiver_GivenThePipeHasSpareCapacity_ReturnsAReceiver()
        {
            // Act
            var receiver = capacityThreePipe.FindReceiver(capacityThreePipe.Inlet);

            // Assert
            receiver.Should().NotBeNull();
        }