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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_screen_size(self, screen_no):
 """Returns the size of the given screen number"""

    return GetScreenSize(display=self.display,
                         opcode=self.display.get_extension_major(extname),
                         window=self.id,
                         screen=screen_no,
                         )