@@ -229,21 +229,21 @@
  *	  specified object.
  *
  * @param object The object which is checked for being in the dictionary
  * @return A boolean whether the dictionary contains the specified object
  */
-- (bool)containsObject: (nullable ObjectType)object;
+- (bool)containsObject: (ObjectType)object;
 
 /*!
  * @brief Checks whether the dictionary contains an object with the specified
  *	  address.
  *
  * @param object The object which is checked for being in the dictionary
  * @return A boolean whether the dictionary contains an object with the
  *	   specified address
  */
-- (bool)containsObjectIdenticalTo: (nullable ObjectType)object;
+- (bool)containsObjectIdenticalTo: (ObjectType)object;
 
 /*!
  * @brief Returns an array of all keys.
  *
  * @return An array of all keys