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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 is_visible(self, x, y):
 """ Return whether the specified location is on the visible screen. :param x: The column (x coord) for the location to check. :param y: The line (y coord) for the location to check. """

        return ((x >= 0) and
                (x <= self.width) and
                (y >= self._start_line) and
                (y < self._start_line + self.height))