code: public static <V> IntObjectHashMap<V> createPrimitiveIntKeyMap(int initialCapacity, float loadFactor) {
  		return new IntObjectHashMap<V>(initialCapacity, loadFactor);
  	}
docs: 创建移植自Netty的key为int的优化HashMap
  
  @param initialCapacity 默认为8
  @param loadFactor 默认为0.5