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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 box(self, x0, y0, width, height):
 """Create a box on ASCII canvas. Args: x0 (int):
 x coordinate of the box corner. y0 (int):
 y coordinate of the box corner. width (int):
 box width. height (int):
 box height. """

        assert width > 1
        assert height > 1

        width -= 1
        height -= 1

        for x in range(x0, x0 + width):
            self.point(x, y0, "-")
            self.point(x, y0 + height, "-")

        for y in range(y0, y0 + height):
            self.point(x0, y, "|")
            self.point(x0 + width, y, "|")

        self.point(x0, y0, "+")
        self.point(x0 + width, y0, "+")
        self.point(x0, y0 + height, "+")
        self.point(x0 + width, y0 + height, "+")