Webix Grid Access to private method!

I am extending one object of webix. Now I am overriding particular method that contain my own logic,
I want the some of the older logic of that method.
But older logic code that I want is defined by private method.
How can I access private method and variable in such case?
Method staring from ‘_’ eg _id

Accessing private methods is possible only if you are using debug version
( in production version names of private methods are mangled and can’t be called directly )

The only stable solution will be to use a debug version of webix.js and use some custom tools ( UglifyJS for example ) to compress it for production usage.

Can you provide some more info about private property which you want to call. Some of them has public aliases.