code: protected File getDataFile(@NotNull final String key) {
          final String file = getString(key);
          LOGGER.debug("Settings.getDataFile() - file: '{}'", file);
          if (file == null) {
              return null;
          }
          if (file.startsWith("[JAR]")) {
              LOGGER.debug("Settings.getDataFile() - transforming filename");
              final File jarPath = getJarPath();
              LOGGER.debug("Settings.getDataFile() - jar file: '{}'", jarPath.toString());
              final File retVal = new File(jarPath, file.substring(6));
              LOGGER.debug("Settings.getDataFile() - returning: '{}'", retVal.toString());
              return retVal;
          }
          return new File(file);
      }
docs: Returns a value from the properties file as a File object. If the value
  was specified as a system property or passed in via the -Dprop=value
  argument - this method will return the value from the system properties
  before the values in the contained configuration file.
  
  This method will check the configured base directory and will use this as
  the base of the file path. Additionally, if the base directory begins
  with a leading "[JAR]\" sequence with the path to the folder containing
  the JAR file containing this class.
  
  @param key the key to lookup within the properties file
  @return the property from the properties file converted to a File object