You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: image.rb
    path of file: ./repos/SlideHub/lib/slide_hub
    
    the code of the file until where you have to start completion: require 'rubygems'
require 'rmagick'

module SlideHub
  class Image
    
    def thumbnail(src, dest)
      width = 320
      height = 240

      thumb = Magick::Image.from_blob(File.read(src)).shift
      thumb_out = if thumb.columns < width || thumb.rows < height
                    cover_white(thumb, width, height)
                  else
                    shrink_to_fill(thumb, width, height)
                  end