The documentation and example say that the argument "4.0.0beta" would perform the code even when the current version is "4.0.0beta". But actually, the code checks if the version comparsion is smaller than 1. This means, that the code will not performed if the current version is 4.0.0beta
So, the documentation should say: Specify the version in which the function won't be called.
Maybe, this is issued by the build number (Ext.Version.compare(Ext.getVersion('extjs'), '184.108.40.206') == 0. Should this be correct?