Method checkKey

src/java/org/apache/poi/util/BinaryTree.java:1221–1224

check a key for validity (non-null and implements Comparable) @param key the key to be checked @exception NullPointerException if key is null @exception ClassCastException if key is not Comparable

(Object key)

     * @exception ClassCastException if key is not Comparable
     */
    private static void checkKey(Object key)
    {
        checkNonNullComparable(key, _KEY);
    }

    /**
     * check a value for validity (non-null and implements Comparable)