# File lib/net/http/persistent.rb, line 826
  def proxy_from_env
    env_proxy = ENV['http_proxy'] || ENV['HTTP_PROXY']

    return nil if env_proxy.nil? or env_proxy.empty?

    uri = URI normalize_uri env_proxy

    env_no_proxy = ENV['no_proxy'] || ENV['NO_PROXY']

    # '*' is special case for always bypass
    return nil if env_no_proxy == '*' 

    if env_no_proxy then
      uri.query = "no_proxy=#{escape(env_no_proxy)}"
    end 

    unless uri.user or uri.password then
      uri.user     = escape ENV['http_proxy_user'] || ENV['HTTP_PROXY_USER']
      uri.password = escape ENV['http_proxy_pass'] || ENV['HTTP_PROXY_PASS']
    end

    uri
  end