### Question:
StringComplexFieldActions implements AtlasFieldAction { @AtlasActionProcessor public static String padStringRight(PadStringRight padStringRight, String input) { if (padStringRight == null || padStringRight.getPadCharacter() == null || padStringRight.getPadCount() == null) { throw new IllegalArgumentException("PadStringRight must be specified with padCharacter and padCount"); } StringBuilder builder = new StringBuilder(); if (input != null) { builder.append(input); } for (int i = 0; i < padStringRight.getPadCount(); i++) { builder.append(padStringRight.getPadCharacter()); } return builder.toString(); }  @AtlasActionProcessor static String append(Append append, String input); @AtlasActionProcessor(sourceType = FieldType.ANY) static String concatenate(Concatenate concat, List<String> inputs); @AtlasActionProcessor static Boolean endsWith(EndsWith endsWith, String input); @AtlasActionProcessor static String format(Format format, List<Object> input); @AtlasActionProcessor static String genareteUUID(GenerateUUID action); @AtlasActionProcessor static Number indexOf(IndexOf indexOf, String input); @AtlasActionProcessor static Number lastIndexOf(LastIndexOf lastIndexOf, String input); @AtlasActionProcessor static String padStringRight(PadStringRight padStringRight, String input); @AtlasActionProcessor static String padStringLeft(PadStringLeft padStringLeft, String input); @AtlasActionProcessor static String prepend(Prepend action, String input); @AtlasActionProcessor static String replaceAll(ReplaceAll replaceAll, String input); @AtlasActionProcessor static String replaceFirst(ReplaceFirst replaceFirst, String input); @AtlasActionProcessor(sourceType = FieldType.ANY) static String[] split(Split split, String input); @AtlasActionProcessor(sourceType = FieldType.ANY) static String[] repeat(Repeat repeat, String input); @AtlasActionProcessor static Boolean startsWith(StartsWith startsWith, String input); @AtlasActionProcessor static String subString(SubString subString, String input); @AtlasActionProcessor static String subStringAfter(SubStringAfter subStringAfter, String input); @AtlasActionProcessor static String subStringBefore(SubStringBefore subStringBefore, String input); static final String STRING_SEPARATOR_REGEX; static final Pattern STRING_SEPARATOR_PATTERN; }### Answer:
@Test public void testPadStringRight() { PadStringRight padStringRight = new PadStringRight(); padStringRight.setPadCharacter("a"); padStringRight.setPadCount(3); assertEquals("aaa", StringComplexFieldActions.padStringRight(padStringRight, null)); assertEquals("aaa", StringComplexFieldActions.padStringRight(padStringRight, "")); assertEquals("aaaa", StringComplexFieldActions.padStringRight(padStringRight, "a")); assertEquals("baaa", StringComplexFieldActions.padStringRight(padStringRight, "b")); try { StringComplexFieldActions.padStringRight(null, "aa"); fail("IllegalArgumentException expected"); } catch (IllegalArgumentException e) { } try { StringComplexFieldActions.padStringRight(new PadStringRight(), "aa"); fail("IllegalArgumentException expected"); } catch (IllegalArgumentException e) { } try { PadStringRight incomplete = new PadStringRight(); incomplete.setPadCharacter("f"); StringComplexFieldActions.padStringRight(incomplete, "aa"); fail("IllegalArgumentException expected"); } catch (IllegalArgumentException e) { } try { PadStringRight incomplete = new PadStringRight(); incomplete.setPadCount(3); StringComplexFieldActions.padStringRight(incomplete, "aa"); fail("IllegalArgumentException expected"); } catch (IllegalArgumentException e) { } }