<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def scroll(self, x, y):
 """Scroll the contents of the console in the direction of x,y. Uncovered areas will be cleared to the default background color. Does not move the virutal cursor. Args: x (int):
 Distance to scroll along the x-axis. y (int):
 Distance to scroll along the y-axis. Returns: Iterator[Tuple[int, int]]: An iterator over the (x, y) coordinates of any tile uncovered after scrolling. .. seealso:: :any:`set_colors` """

        assert isinstance(x, _INTTYPES), "x must be an integer, got %s" % repr(x)
        assert isinstance(y, _INTTYPES), "y must be an integer, got %s" % repr(x)
        def getSlide(x, length):
            """get the parameters needed to scroll the console in the given
            direction with x
            returns (x, length, srcx)
            """
            if x > 0:
                srcx = 0
                length -= x
            elif x < 0:
                srcx = abs(x)
                x = 0
                length -= srcx
            else:
                srcx = 0
            return x, length, srcx
        def getCover(x, length):
            """return the (x, width) ranges of what is covered and uncovered"""
            cover = (0, length) # everything covered
            uncover = None  # nothing uncovered
            if x > 0: # left side uncovered
                cover = (x, length - x)
                uncover = (0, x)
            elif x < 0: # right side uncovered
                x = abs(x)
                cover = (0, length - x)
                uncover = (length - x, x)
            return cover, uncover

        width, height = self.get_size()
        if abs(x) >= width or abs(y) >= height:
            return self.clear() # just clear the console normally

        # get the ranges of the areas that will be uncovered
        coverX, uncoverX = getCover(x, width)
        coverY, uncoverY = getCover(y, height)
        # so at this point we know that coverX and coverY makes a rect that
        # encases the area that we end up blitting to.  uncoverX/Y makes a
        # rect in the corner of the uncovered area.  So we need to combine
        # the uncoverX/Y with coverY/X to make what's left of the uncovered
        # area.  Explaining it makes it mush easier to do now.

        # But first we need to blit.
        x, width, srcx = getSlide(x, width)
        y, height, srcy = getSlide(y, height)
        self.blit(self, x, y, width, height, srcx, srcy)
        if uncoverX: # clear sides (0x20 is space)
            self.draw_rect(uncoverX[0], coverY[0], uncoverX[1], coverY[1],
                           0x20, self._fg, self._bg)
        if uncoverY: # clear top/bottom
            self.draw_rect(coverX[0], uncoverY[0], coverX[1], uncoverY[1],
                           0x20, self._fg, self._bg)
        if uncoverX and uncoverY: # clear corner
            self.draw_rect(uncoverX[0], uncoverY[0], uncoverX[1], uncoverY[1],
                           0x20, self._fg, self._bg)