@@ -884,5 +884,11 @@
 /**
  * An OFException indicating that unlocking a mutex failed.
  */
 @interface OFMutexUnlockFailedException: OFException {}
 @end
+
+/**
+ * An OFException indicating that the hash has already been calculated.
+ */
+@interface OFHashAlreadyCalculatedException: OFException {}
+@end