protected void logArgValue(String key, String description, Object result) {
    if (!silent && LOGGER.isDebugEnabled()) {
      LOGGER.debug("argument: {}={} ({})", key.replaceFirst("\\|.*$", ""), result, description);
    }
  }
Returns an {@link Envelope} parsed from {@code key} argument, or null if missing.
<p>
Format: {@code westLng,southLat,eastLng,northLat}

@param key         argument name
@param description argument description
@return An envelope parsed from {@code key} or null if missing
planetiler-core/src/main/java/com/onthegomap/planetiler/config/Arguments.java