code: public boolean contains(int value) {
  
          Entry tab[] = table;
          for (int i = tab.length; i-- > 0;) {
              for (Entry e = tab[i]; e != null; e = e.next) {
                  if (e.value == value) {
                      return true;
                  }
              }
          }
          return false;
       }
docs: *
  <p>Tests if some key maps into the specified value in this hashtable.
  This operation is more expensive than the <code>containsKey</code>
  method.</p>
  
  <p>Note that this method is identical in functionality to containsValue,
  (which is part of the Map interface in the collections framework).</p>
  
  @param      value   a value to search for.
  @return     <code>true</code> if and only if some key maps to the
  <code>value</code> argument in this hashtable as
  determined by the <tt>equals</tt> method;
  <code>false</code> otherwise.
  @throws  NullPointerException  if the value is <code>null</code>.
  @see        #containsKey(int)
  @see        #containsValue(int)
  @see        java.util.Map