docs: static byte[] writePlanBytes(VoltCompiler compiler, PlanFragment fragment, AbstractPlanNode planGraph)
      throws VoltCompilerException {
          String json = null;
          // get the plan bytes
          PlanNodeList node_list = new PlanNodeList(planGraph, false);
          json = node_list.toJSONString();
          compiler.captureDiagnosticJsonFragment(json);
          // Place serialized version of PlanNodeTree into a PlanFragment
          byte[] jsonBytes = json.getBytes(Charsets.UTF_8);
          String bin64String = CompressionService.compressAndBase64Encode(jsonBytes);
          fragment.setPlannodetree(bin64String);
          return jsonBytes;
      }