private String format(double duration, Units units)
  {
    StringBuilder builder = new StringBuilder();
    builder.append(numberFormat.format(duration));
    builder.append(' ');
    builder.append(units.display());
    return builder.toString();
  }
private String format ( double duration , Units units ) { StringBuilder builder = new StringBuilder ( ) ; builder . append ( numberFormat . format ( duration ) ) ; builder . append ( ' ' ) ; builder . append ( units . display ( ) ) ; return builder . toString ( ) ; }
Build time duration representation for given numeric value and units.

@param duration duration numeric part value,
@param units bit rate units.
@return formated bit rate.