# File lib/faraday/connection.rb, line 98
    def proxy(arg = nil)
      return @proxy if arg.nil?

      @proxy = 
        case arg
          when String then {:uri => proxy_arg_to_uri(arg)}
          when URI    then {:uri => arg}
          when Hash   then arg
            if arg[:uri] = proxy_arg_to_uri(arg[:uri])
              arg
            else
              raise ArgumentError, "no :uri option."
            end
        end
    end