code: public void setEdgeTreatments(
              EdgeTreatment leftEdge,
              EdgeTreatment topEdge,
              EdgeTreatment rightEdge,
              EdgeTreatment bottomEdge) {
          this.leftEdge = leftEdge;
          this.topEdge = topEdge;
          this.rightEdge = rightEdge;
          this.bottomEdge = bottomEdge;
      }
docs: Sets edge treatments.
  
  @param leftEdge   the edge treatment to use on the left edge.
  @param topEdge    the edge treatment to use on the top edge.
  @param rightEdge  the edge treatment to use on the right edge.
  @param bottomEdge the edge treatment to use on the bottom edge.