code: public ParallelTaskBuilder setReplaceVarMapToSingleTarget(
              List<StrStrMap> replacementVarMapList, String uniformTargetHost) {
  
          if (Strings.isNullOrEmpty(uniformTargetHost)) {
              logger.error("uniform target host is empty or null. skil setting.");
              return this;
          }
          this.replacementVarMapNodeSpecific.clear();
          this.targetHosts.clear();
          int i = 0;
          for (StrStrMap ssm : replacementVarMapList) {
              if (ssm == null)
                  continue;
              String hostName = PcConstants.API_PREFIX + i;
              ssm.addPair(PcConstants.UNIFORM_TARGET_HOST_VAR, uniformTargetHost);
              replacementVarMapNodeSpecific.put(hostName, ssm);
              targetHosts.add(hostName);
              ++i;
          }
          this.requestReplacementType = RequestReplacementType.TARGET_HOST_SPECIFIC_VAR_REPLACEMENT;
          logger.info(
                  "Set requestReplacementType as {} for single target. Will disable the set target hosts."
                          + "Also Simulated "
                          + "Now Already set targetHost list with size {}. \nPLEASE NOT TO SET TARGET HOSTS AGAIN WITH THIS API.",
                  requestReplacementType.toString(), targetHosts.size());
  
          return this;
      }
docs: Sets the replace var map to single target.
  
  @param replacementVarMapList
  the replacement var map list
  @param uniformTargetHost
  the uniform target host
  @return the parallel task builder