code: public static BtcFormat getInstance(Style style, Locale locale, int fractionPlaces) {
          return new BtcAutoFormat(locale, style, fractionPlaces);
      }
docs: Return a new auto-formatter for the given locale with the given number of fraction places.
  The returned object will automatically-denominate each formatted
  value, and will indicate that denomination using either a currency code,
  such as {@code "mBTC"}, or symbol, such as {@code "฿"},
  according to the given style argument.  It will format each number
  according to the given locale.
  
  <p>The third parameter is the number of fractional decimal places to use for each
  formatted number, reduced as necessary when formatting to avoid giving a place to
  fractional satoshis.