README.md in frontkick-0.3.3 vs README.md in frontkick-0.3.4

@@ -37,9 +37,13 @@
 
 Prohibit another process to run a command concurrently
 
     Frontkick.exec("sleep 2 && ls /hoge", :exclusive => "/tmp/frontkick.lock") # raises Fontkick::Locked if locked
 
+If you prefer to be blocked:
+
+    Frontkick.exec("sleep 2 && ls /hoge", :exclusive => "/tmp/frontkick.lock", :exclusive_blocking => true)
+
 ## Contributing
 
 1. Fork it
 2. Create your feature branch (`git checkout -b my-new-feature`)
 3. Commit your changes (`git commit -am 'Add some feature'`)