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: meme_generator.rb
    path of file: ./repos/lgtm_hd/lib/lgtm_hd
    
    the code of the file until where you have to start completion: require "mini_magick"

module LgtmHD
  class MemeGenerator
    @@caption_positions = {caption_position_top: "north center", caption_position_bottom: "south center"}

    # TODO make options lis
    
    def draw(caption_text = "LGTM")
      img = image
      img.combine_options do |c|
        c.gravity caption_position
        c.draw "text 0,0 " << caption_text
        c.font caption_font
        c.pointsize caption_font_size
        c.density image_density
        c.fill caption_color
        c.resize image_max_size().reduce() {|w,h| "#{w}x#{h}"} # syntax: convert -resize $wx$h
        img.contrast
      end
      yield img if block_given?
    end