UnmodifiableMap(Map m) 
{
               
            if (m==null)
                throw new NullPointerException();
            this.m = m;
}

 public  void clear() 
{
            throw new UnsupportedOperationException();
}

 public boolean containsKey(Object key) 
{
return m.containsKey(key);
}

 public boolean containsValue(Object val) 
{
return m.containsValue(val);
}

 public Set entrySet() 
{
            if (entrySet==null)
                entrySet = new UnmodifiableEntrySet< K,V >(m.entrySet());
            return entrySet;
}

 public boolean equals(Object o) 
{
return o == this || m.equals(o);
}

 public V get(Object key) 
{
return m.get(key);
}

 public int hashCode() 
{
return m.hashCode();
}

 public boolean isEmpty() 
{
return m.isEmpty();
}

 public Set keySet() 
{
           
            if (keySet==null)
                keySet = unmodifiableSet(m.keySet());
            return keySet;
}

 public V put(K key,
    V value) 
{
            throw new UnsupportedOperationException();
}

 public  void putAll(Map m) 
{
            throw new UnsupportedOperationException();
}

 public V remove(Object key) 
{
            throw new UnsupportedOperationException();
}

 public int size() 
{
return m.size();
}

 public String toString() 
{
return m.toString();
}

 public Collection values() 
{
            if (values==null)
                values = unmodifiableCollection(m.values());
            return values;
}