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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_from(self, x, y):
 """ Get the character at the specified location. :param x: The column (x coord) of the character. :param y: The row (y coord) of the character. :return: A 4-tuple of (ascii code, foreground, attributes, background) for the character at the location. """

        # Convert to buffer coordinates
        y -= self._start_line
        if y < 0 or y >= self._buffer_height or x < 0 or x >= self.width:
            return None
        cell = self._buffer.get(x, y)
        return cell[0], cell[1], cell[2], cell[3]