get_modal
Description:
Returns whether the file chooser dialog blocks interaction with the parent window while it is presented.
Parameters:
| this | 
           a file dialog  | 
      
Returns:
| 
           true if the file chooser dialog is modal  | 
      
Returns whether the file chooser dialog blocks interaction with the parent window while it is presented.
| this | 
           a file dialog  | 
      
| 
           true if the file chooser dialog is modal  |