code: public static final Function<String,BigInteger> toBigInteger(final RoundingMode roundingMode, final Locale locale) {
          return new ToBigInteger(roundingMode, locale);
      }
docs: <p>
  Converts a String into a BigInteger, using the specified locale for determining
  decimal point. Rounding mode is used for removing the
  decimal part of the number.
  Any fractional part of the input String will be removed.
  </p>
  
  @param roundingMode the rounding mode to be used when setting the scale
  @param locale the locale defining the way in which the number was written
  @return the resulting BigInteger object