code: @Override
    public boolean containsValue(final Object value) {
      for (OMVRBTreeEntry<K, V> e = getFirstEntry(); e != null; e = next(e))
        if (valEquals(value, e.getValue()))
          return true;
      return false;
    }
docs: Returns <tt>true</tt> if this map maps one or more keys to the specified value. More formally, returns <tt>true</tt> if and
  only if this map contains at least one mapping to a value <tt>v</tt> such that
  <tt>(value==null ? v==null : value.equals(v))</tt>. This operation will probably require time linear in the map size for most
  implementations.
  
  @param value
  value whose presence in this map is to be tested
  @return <tt>true</tt> if a mapping to <tt>value</tt> exists; <tt>false</tt> otherwise
  @since 1.2