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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 point(self, x, y, char):
 """Create a point on ASCII canvas. Args: x (int):
 x coordinate. Should be >= 0 and < number of columns in the canvas. y (int):
 y coordinate. Should be >= 0 an < number of lines in the canvas. char (str):
 character to place in the specified point on the canvas. """

        assert len(char) == 1
        assert x >= 0
        assert x < self.cols
        assert y >= 0
        assert y < self.lines

        self.canvas[y][x] = char