# File lib/compass/grid_builder.rb, line 85
    def generate!
      (0...@height-1).each do |line|
        @data[line] = Array.new(@width){|x| x < @column_width ? [0xe8, 0xef, 0xfb] : [0xff,0xff,0xff] }
      end

      if File.exists?(filename)
        if options[:force]
          overwrite = true
        else
          msg = "#{filename} already exists. Overwrite with --force."
          raise Compass::FilesystemConflict.new(msg)
        end
      end
      directory File.dirname(filename)
      write_file(filename, self.to_blob, options, true)
    end