A message box for “Edit Extended Apex Class” will appear when the “Direct Editing on Studio” button is clicked.
Apex Class can be created and edited on Studio without selecting deployed Apex Class. Also, Test Class must be creates as a different Class.

Apex Classes that are edited directly will deploy simultaneously when the new page is created.
When you are setting Apex Class that is edited directly in the Studio, you cannot specify a deployed Class.
Please refer to < 5-1. Apex Class Extension > for more information on Extended Apex Class's interface and processes.

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