line from 0,0  right 1 then up 1 then right 1 then down 1.5 \
   then left 0.6 dashed;
spline from 0,0  right 1 then up 1 then right 1 then down 1.5 \
   then left 0.6

circle fill white \
  at 1/2 between 4th vertex of previous and 5th vertex of previous
spline -> from last circle.e go right then heading 30 then heading 45 \
   then heading 60 then heading 75
