z.load() Must be used before SparkInterpreter (%spark) initialized?

[Richard Xin]

I used %depz.load("path/to/jar")I got following error:Must be used before 
SparkInterpreter (%spark) initializedHint: put this paragraph before any Spark 
code and restart Zeppelin/Interpreter
restart zeppelin did make it work, it seems to be an expected behavior, but I 
don't understand thee reason behind it. If every time I have to restart 
zeppelin before I could dynamically add an external jar, then this feature is 
useless to most people.
Richard Xin