CheckedMap(Map m,
    Class keyType,
    Class valueType) 
{
            if (m == null || keyType == null || valueType == null)
                throw new NullPointerException();
            this.m = m;
            this.keyType = keyType;
            this.valueType = valueType;
}

 public  void clear() 
{
 m.clear();
}

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

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

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

 public V put(K key,
    V value) 
{
            typeCheck(key, value);
            return m.put(key, value);
}

 public  void putAll(Map t) 
{
            // Satisfy the following goals:
            // - good diagnostics in case of type mismatch
            // - all-or-nothing semantics
            // - protection from malicious t
            // - correct behavior if t is a concurrent map
            Object[] entries = t.entrySet().toArray();
            List< Map.Entry< K,V > > checked =
                new ArrayList< Map.Entry< K,V > >(entries.length);
            for (Object o : entries) {
                Map.Entry< ?,? > e = (Map.Entry< ?,? >) o;
                Object k = e.getKey();
                Object v = e.getValue();
                typeCheck(k, v);
                checked.add(
                    new AbstractMap.SimpleImmutableEntry< K,V >((K) k, (V) v));
            }
            for (Map.Entry< K,V > e : checked)
                m.put(e.getKey(), e.getValue());
}

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

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

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

 public Collection values() 
{
 return m.values();
}