code: public static final Function<Number,String> toStr(Locale locale, boolean groupingUsed) {
          return new ToString(locale, groupingUsed);
      }
docs: <p>
  It returns the {@link String} representation of the target number in the given {@link Locale}. Grouping
  will be used depending on the value of the groupingUsed parameter
  </p>
  
  @param locale the {@link Locale} to be used
  @param groupingUsed whether or not grouping will be used
  @return the {@link String} representation of the input