docs: private boolean separatorDown(Rectangular pos)
      {
          if (pos.getY2() < getTopology().getTopologyHeight()-1)
          {
              Rectangular spos = getTopology().toPixelPositionAbsolute(new Rectangular(pos.getX1(), pos.getY2(), pos.getX2(), pos.getY2()));
              Rectangular epos = getTopology().toPixelPositionAbsolute(new Rectangular(pos.getX1(), pos.getY2() + 1, pos.getX2(), pos.getY2() + 1));
              return seps.isSeparatorAt(spos.midX(), spos.getY2()) ||
                     seps.isSeparatorAt(epos.midX(), epos.getY1());
          }
          else
              return true;
      }