public int put(Object key,int value){
  if (key == null)   key=NULL_KEY;
synchronized (this) {
    int hash=key.hashCode() & _mask;
    for (Item item=_entries[hash]; item != null; item=item._next) {
      Object testKey=item._key;
      if (testKey == key || testKey.equals(key)) {
        int oldValue=item._value;
        item._value=value;
        return oldValue;
      }
    }
    Item item=new Item(key,value);
    item._next=_entries[hash];
    _entries[hash]=item;
    _size++;
  }
  return NULL;
}

public int put ( Object key , int value ) { if ( key == null ) key = NULL_KEY ; synchronized ( this ) { int hash = key . hashCode ( ) & _mask ; for ( Item item = _entries [ hash ] ; item != null ; item = item . _next ) { Object testKey = item . _key ; if ( testKey == key || testKey . equals ( key ) ) { int oldValue = item . _value ; item . _value = value ; return oldValue ; } } Item item = new Item ( key , value ) ; item . _next = _entries [ hash ] ; _entries [ hash ] = item ; _size ++ ; } return NULL ; }
puts a new value in the property table with the appropriate flags
