关于 HashTable

　　/**
     * Constructs a new, empty hashtable with a default initial capacity (11)
     * and load factor (0.75).
     */
    public Hashtable() { 
        this(11, 0.75f);
    }

/**
 * Constructs a new, empty hashtable with the specified initial capacity
 * and default load factor (0.75).
 *
 * @param     initialCapacity   the initial capacity of the hashtable.
 * @exception IllegalArgumentException if the initial capacity is less
 *              than zero.
 */
public Hashtable(int initialCapacity) {
    this(initialCapacity, 0.75f);
}