Moves a layer up or down in the viewer zorder list (only visible layers). This procedure takes into account only visible layers; invisible layers (HideFromLegend=True) located after current layer will be moved together. If current layer is not visible, then the nearest visible (but previous on the Items list) layer will be used as an anchor.
# Python def MoveEx( self, _step: int ) -> None:
|_step||int||how many steps and in which direction a layer must be moved; negative values mean movement to the front.|