code: public static String getLatkeProperty(final String key) {
          String ret = latkeProps.getProperty(key);
          if (StringUtils.isBlank(ret)) {
              return ret;
          }
  
          ret = replaceEnvVars(ret);
  
          return ret;
      }
docs: Gets a property specified by the given key from file "latke.properties".
  
  @param key the given key
  @return the value, returns {@code null} if not found