### Question:
Util { public static String encodeXmlAttribute(String string) { if (string == null) { return null; } int len = string.length(); if (len == 0) { return string; } StringBuilder encoded = new StringBuilder(); for (int i = 0; i < len; i++) { char c = string.charAt(i); if (c == '<') { encoded.append("&lt;"); } else if (c == '\"') { encoded.append("&quot;"); } else if (c == '>') { encoded.append("&gt;"); } else if (c == '\'') { encoded.append("&apos;"); } else if (c == '&') { encoded.append("&amp;"); } else { encoded.append(c); } } return encoded.toString(); }  static File toFile(URL url); static String stringFromFile(File file); static String stringFromFile(File file, String joinWith); static String join(Iterable<?> objects, String separator); static String substBackslashes(String string); static Throwable unwindException(Throwable th); static boolean nullSafeEquals(Object o1, Object o2); static int nullSafeCompare(boolean nullsFirst, Comparable<T> o1, T o2); static boolean isEmptyString(CharSequence string); static boolean isBlank(CharSequence cs); static boolean isNumeric(CharSequence cs); static int countMatches(final String str, final String sub); static String capitalized(String name); static String uncapitalized(String aString); @SuppressWarnings("unchecked") static T cloneViaSerialization(T object); static XMLReader createXmlReader(); static Document readDocument(URL url); static String getPackagePath(String className); static String stripPackageName(String className); static Map<K, V> toMap(K[] keys, V[] values); static String extractFileExtension(String fileName); static String stripFileExtension(String fileName); static String stripLineBreaks(String string, char replaceWith); static String encodeXmlAttribute(String string); static String prettyTrim(String str, int maxLength); static Iterator<T> sortedIterator(Iterator<T> it, Comparator<T> comparator); static int hashCode(Collection<?> c); static Pattern sqlPatternToPattern(String pattern, boolean ignoreCase); static boolean isAccessible(Member member); @Deprecated static Class<?> getJavaClass(String className); static String underscoredToJava(String name, boolean capitalize); static String specialCharsToJava(String string);  }### Answer:
@Test public void testEncodeXmlAttribute1() throws Exception { String unencoded = "normalstring"; assertEquals(unencoded, Util.encodeXmlAttribute(unencoded)); }
@Test public void testEncodeXmlAttribute2() throws Exception { String unencoded = "<a>"; assertEquals("&lt;a&gt;", Util.encodeXmlAttribute(unencoded)); }
@Test public void testEncodeXmlAttribute3() throws Exception { String unencoded = "a&b"; assertEquals("a&amp;b", Util.encodeXmlAttribute(unencoded)); }