All use of class/module variables should declare (or define them,) near the top of the code.
If you reference them, or ruby encounters them before they have been initialized, a Runtime error occurs.
I do this even when I will later set them to a command or a string, etc.
It is a good place (at the top of the code) to put a comment explaining what the variables will be used for.
@@rotate_cmd = nil # UI::Command instance for rotator tool
FYI, definition of class/module variables cannot use the ||= syntax because that expands to
@@var = @@var || value
… which would be referencing @@var just to the right of the assignment operator, before it is initailized.
BTW,… did we just abandon the previous topic ?
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