code: public ParallelTaskBuilder setReplaceVarMapToSingleTargetSingleVar(
              String variable, List<String> replaceList, 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 (String replace : replaceList) {
              if (replace == null){
                  logger.error("null replacement.. skip");
                  continue;
              }
              String hostName = PcConstants.API_PREFIX + i;
  
              replacementVarMapNodeSpecific.put(
                      hostName,
                      new StrStrMap().addPair(variable, replace).addPair(
                              PcConstants.UNIFORM_TARGET_HOST_VAR,
                              uniformTargetHost));
              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 single var.
  
  @param variable
  the variable
  @param replaceList
  : the list of strings that will replace the variable
  @param uniformTargetHost
  the uniform target host
  @return the parallel task builder