Tools { public static double percentOf(final double percent, final double total) { return (percent / 100.0) * total; } private  Tools(); static String getTime(); static String getDoubleDigit(final int number); static String dateToString(@Nullable final Date d, final String format); static String decimalFormat(final String format, final double number); static boolean isValidNick(@Nullable final String nick); static String byteToString(final long bytes); static int getBytes(final String text); static void sleep(final long millis); @Nullable static String capitalizeFirstLetter(@Nullable final String word); @Nullable static String shorten(@Nullable final String word, final int length); @Nullable static String getFileExtension(@Nullable final String filename); @Nullable static String getFileBaseName(@Nullable final String filename); static double percent(final double fraction, final double total); static double percentOf(final double percent, final double total); static String postPadString(final String stringToPad, final int paddedLength); static boolean isEmpty(@Nullable final String string); static String appendSlash(final String path); static File getFileWithIncrementedName(final File existingFile); static String emptyIfNull(@Nullable final String string);  }
@Test public void testPercentOf() { assertEquals(1, Tools.percentOf(0.08, 1250), 10); assertEquals(50, Tools.percentOf(25, 200), 10); assertEquals(5, Tools.percentOf(50, 10), 10); assertEquals(10, Tools.percentOf(100, 10), 10); assertEquals(60, Tools.percentOf(200, 30), 10); }