Think about filtering just the side component by an high pass filter to get rid of stereo information in
the bass frequencies for example.
The module creates the sum and the difference of the left and right channel to
extract the mid (sum) and side (difference) signal. To restore the left / right
stereo signal from the mid/side signal the mid-signal is just routed both to the
internal left and the right output signal bus of the module while the side signal
will be added to that bus differentially (non inverted to the left output and
inverted to the right output).
This module can be very useful formanipulation of the stereo image of an stereo audio signal.