docs: private String getValueTypeDotString() {
          PlanNodeType pnt = getPlanNodeType();
          if (isInline()) {
              return "fontcolor=\"white\" style=\"filled\" fillcolor=\"red\"";
          }
          if (pnt == PlanNodeType.SEND || pnt == PlanNodeType.RECEIVE || pnt == PlanNodeType.MERGERECEIVE) {
              return "fontcolor=\"white\" style=\"filled\" fillcolor=\"black\"";
          }
          return "";
      }