### Question:
Element implements Serializable, Cloneable { public final boolean equals(Object object) { if (object == null || !(object instanceof Element)) { return false; } Element element = (Element) object; if (key == null || element.getObjectKey() == null) { return false; } return key.equals(element.getObjectKey()); } Element(Serializable key, Serializable value, long version);  Element(Object key, Object value, long version);  Element(Object key, Object value, long version,
                   long creationTime, long lastAccessTime,
                   long nextToLastAccessTime, long lastUpdateTime,
                   long hitCount);  Element(Object key, Object value,
                   Boolean eternal, Integer timeToIdleSeconds, Integer timeToLiveSeconds);  Element(Serializable key, Serializable value);  Element(Object key, Object value); final Serializable getKey(); final Object getObjectKey(); final Serializable getValue(); final Object getObjectValue(); final boolean equals(Object object); void setTimeToLive(int timeToLiveSeconds); void setTimeToIdle(int timeToIdleSeconds); final int hashCode(); final void setVersion(long version); final long getCreationTime(); final long getLatestOfCreationAndUpdateTime(); final void setCreateTime(); final long getVersion(); final long getLastAccessTime(); final long getNextToLastAccessTime(); final long getHitCount(); final void resetAccessStatistics(); final void updateAccessStatistics(); final void updateUpdateStatistics(); final String toString(); final Object clone(); final long getSerializedSize(); final boolean isSerializable(); final boolean isKeySerializable(); long getLastUpdateTime(); boolean isExpired(); long getExpirationTime(); boolean isEternal(); void setEternal(boolean eternal); boolean isLifespanSet(); int getTimeToLive(); int getTimeToIdle(); Set getGroupKeys(); void setGroupKeys(Set groupKeys); boolean hasGroupKeys(); boolean addGroupKey(Object groupKey); boolean removeGroupKey(Object groupKey);  }### Answer:
@Test public void testEquals() { Element element = new Element("key", "value"); assertFalse(element.equals("dog")); assertTrue(element.equals(element)); assertFalse(element.equals(null)); assertFalse(element.equals(new Element("cat", "hat"))); }