### Question:
Chars { public static Slice padSpaces(Slice slice, CharType charType) { requireNonNull(charType, "charType is null"); return padSpaces(slice, charType.getLength()); } private  Chars(); @Deprecated static boolean isCharType(Type type); static Slice padSpaces(Slice slice, CharType charType); static Slice padSpaces(Slice slice, int length); static String padSpaces(String value, CharType charType); static Slice truncateToLengthAndTrimSpaces(Slice slice, Type type); static Slice truncateToLengthAndTrimSpaces(Slice slice, CharType charType); static Slice truncateToLengthAndTrimSpaces(Slice slice, int maxLength); static Slice trimTrailingSpaces(Slice slice); static int byteCountWithoutTrailingSpace(Slice slice, int offset, int length); static int byteCountWithoutTrailingSpace(Slice slice, int offset, int length, int codePointCount); static int compareChars(Slice left, Slice right);  }### Answer:
@Test public void testPadSpaces() { String nonBmp = "\uD83D\uDE81"; verify(nonBmp.codePoints().count() == 1, "nonBmp must be a single character (code point) string"); verify(nonBmp.length() == 2, "nonBmp must be encoded as surrogate pairs (2 Java characters)"); testPadSpaces("", 0, ""); testPadSpaces("", 1, " "); testPadSpaces("", 3, " "); testPadSpaces("ab", 3, "ab "); testPadSpaces("abc", 3, "abc"); testPadSpaces(nonBmp, 3, nonBmp + " "); testPadSpaces(nonBmp + nonBmp, 3, nonBmp + nonBmp + " "); testPadSpaces(nonBmp + nonBmp + nonBmp, 3, nonBmp + nonBmp + nonBmp); assertThatThrownBy(() -> padSpaces(nonBmp + nonBmp + nonBmp + nonBmp, createCharType(3))).hasMessage("pad length is smaller than text length"); assertThatThrownBy(() -> padSpaces(utf8Slice(nonBmp + nonBmp + nonBmp + nonBmp), createCharType(3))).hasMessage("pad length is smaller than slice length"); assertThatThrownBy(() -> padSpaces(utf8Slice(nonBmp + nonBmp + nonBmp + nonBmp), 3)).hasMessage("pad length is smaller than slice length"); }