[State Invariant:003]: Create a State Invariant

It SHALL be possible to create (Palette or assistant) a state invariant by providing a location (click point) and optionally a size (drag rectangle). The state invariant will be created in that location or the closest possible location centered on the lifeline body line.

Any existing fragment located after the insertion location will be shifted down by a distance equivalent to the size of the execution specification plus any additional distance needed to keep the predefined minimal distance between fragments.