Change Gmail notifier check interval in Mac OS X

The default check interval of Gmail notifier for Mac is something like 10 minutes and it cannot be changed by any visible menu or option. Here is how to do it: click on the Gmail icon and then while holding Cmd+Opt click on the "Preferences...". There will be a dialog with two fields: key and value. For key enter "AutocheckInterval" and for value enter a number (minutes). Mine is set to 2.