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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 preview(self, page, filelike, format='png', dpi=72, background_colour=0xFFFFFF):
 """Render a preview image of a page. Parameters page: positive integer Which page to render. Must be in the range [1, page_count] filelike: path or file-like object Can be a filename as a string, a Python file object, or something which behaves like a Python file object. For example, if you were using the Django web framework, an HttpResponse object could be passed to render the preview to the browser (as long as you remember to set the mimetype of the response). If you pass a filename, the existing contents will be overwritten. format: string The image format to use for the preview. ReportLab uses the Python Imaging Library (PIL) internally, so any PIL format should be supported. dpi: positive real The dots-per-inch to use when rendering. background_colour: Hex colour specification What color background to use. Notes ----- If you are creating this sheet for a preview only, you can pass the pages_to_draw parameter to the constructor to avoid the drawing function being called for all the labels on pages you'll never look at. If you preview a page you did not tell the sheet to draw, you will get a blank image. Raises ------ ValueError: If the page number is not valid. """

        # Check the page number.
        if page < 1 or page > self.page_count:
            raise ValueError("Invalid page number; should be between 1 and {0:d}.".format(self.page_count))

        # Shade any remaining missing labels if desired.
        self._shade_remaining_missing()

        # Rendering to an image (as opposed to a PDF) requires any background
        # to have an integer width and height if it is a ReportLab Image
        # object. Drawing objects are exempt from this.
        oldw, oldh = None, None
        if isinstance(self._bgimage, Image):
            oldw, oldh = self._bgimage.width, self._bgimage.height
            self._bgimage.width = int(oldw) + 1
            self._bgimage.height = int(oldh) + 1

        # Let ReportLab do the heavy lifting.
        renderPM.drawToFile(self._pages[page-1], filelike, format, dpi, background_colour)

        # Restore the size of the background image if we changed it.
        if oldw:
            self._bgimage.width = oldw
            self._bgimage.height = oldh