public T get(int key) {
        Entry<T>[] tab = table;
        int hash = key;
        int index = (hash & 0x7FFFFFFF) % tab.length;
        for (Entry<T> e = tab[index]; e != null; e = e.next) {
            if (e.hash == hash) {
                return e.value;
            }
        }
        return null;
    }
<p>Returns the value to which the specified key is mapped in this map.</p>

@param   key   a key in the hashtable.
@return  the value to which the key is mapped in this hashtable;
         <code>null</code> if the key is not mapped to any value in
         this hashtable.
@see     #put(int, T)
commons/src/main/java/com/navercorp/pinpoint/common/util/apache/IntHashMap.java