Instantiates and returns a new protocol driver instance for the given protocol version. session must be a valid SFTP session object, and version must be an integer. If an unsupported version is given, an exception will be raised.
    # File lib/net/sftp/protocol.rb, line 18
18:     def self.load(session, version)
19:       case version
20:       when 1 then V01::Base.new(session)
21:       when 2 then V02::Base.new(session)
22:       when 3 then V03::Base.new(session)
23:       when 4 then V04::Base.new(session)
24:       when 5 then V05::Base.new(session)
25:       when 6 then V06::Base.new(session)
26:       else raise NotImplementedError, "unsupported SFTP version #{version.inspect}"
27:       end
28:     end