Large app.js after build

Hi,

I have created a new app using sencha cmd (5.1.0.26)

I have removed all classes except for one that is the application class (all views also removed)

After building the application with "sencha app build" the resulting app.js file is over 1MB!!. What am I doing wrong here? Shouldn't it be much smaller since I "required" very little?

Please advice.

Large app.js after build