module Selenium::WebDriver::Firefox::Features

def install_addon(path, temporary)
  addon = if File.directory?(path)
            Zipper.zip(path)
          else
            File.open(path, 'rb') { |crx_file| Base64.strict_encode64 crx_file.read }
          end
  payload = {addon: addon}
  payload[:temporary] = temporary unless temporary.nil?
  execute :install_addon, {}, payload
end