code: public void setAllEdges(EdgeTreatment edgeTreatment) {
          leftEdge = edgeTreatment.clone();
          topEdge = edgeTreatment.clone();
          rightEdge = edgeTreatment.clone();
          bottomEdge = edgeTreatment.clone();
      }
docs: Sets all edge treatments.
  
  @param edgeTreatment the edge treatment to use for all four edges.