Hi, dear devs! Currently, I'm developing a Helium visualization package.
But, class Visualization <https://github.com/apache/zeppelin/blob/master/zeppelin-web/src/app/visualization/visualization.js> is not clear about abstract methods. It seems like I should override render, but some of them are optional (e.g. refresh, destroy etc.) So, If you let me know which method is mandatory and which one is optional, I would like to create an issue :) A mandatory method should throw an error if not implemented. (Like SpellBase <https://github.com/apache/zeppelin/blob/master/zeppelin-web/src/app/spell/spell-base.js> !) Thanks, -- Taejun Kim Data Mining Lab. School of Electrical and Computer Engineering University of Seoul
