code: void digReplaceContent(Map<String, Object> map) {
  
          map.entrySet().stream().forEach(entry -> {
  
              Object value = entry.getValue();
  
              if (value instanceof Map) {
                  digReplaceContent((Map<String, Object>) value);
  
              } else {
                  LOGGER.debug("Leaf node found = {}, checking for any external json file...", value);
                  if (value != null && value.toString().contains(JSON_PAYLOAD_FILE)) {
                      LOGGER.info("Found external JSON file place holder = {}. Replacing with content", value);
                      String valueString = value.toString();
                      String token = getJsonFilePhToken(valueString);
                      if (token != null && token.startsWith(JSON_PAYLOAD_FILE)) {
                          String resourceJsonFile = token.substring(JSON_PAYLOAD_FILE.length());
                          try {
                              Object jsonFileContent = objectMapper.readTree(readJsonAsString(resourceJsonFile));
                              entry.setValue(jsonFileContent);
                          } catch (Exception exx) {
                              LOGGER.error("External file reference exception - {}", exx.getMessage());
                              throw new RuntimeException(exx);
                          }
                      }
                      // ----------------------------------------------------
                      // Extension- for XML file type in case a ticket raised
                      // ----------------------------------------------------
                      /*
                      else if (token != null && token.startsWith(XML_FILE)) {
  
                      }
                      */
  
                      // ---------------------------------------------------
                      // Extension- for Other types in case a ticket raised
                      // ---------------------------------------------------
                      /*
                      else if (token != null && token.startsWith(OTHER_FILE)) {
  
                      }
                      */
  
                  }
              }
          });
      }
docs: Digs deep into the nested map and looks for external file reference,if found, replaces the place holder with
  the file content. This is handy when the engineers wants to drive the common contents from a central place.
  
  @param map A map representing the key-value pairs, can be nested