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1xx Informational
Benjamin Bouchet
The HTTP Status 100 (Switching Protocols) means that the client has asked the server to change protocols and the server has agreed to do so.
Note that when a Status 101 is returned the server must generate an Upgrade header in its response indicating which protocol it has switched to. Also note that the server should only accept switching protocols (and thus return Status 101) when it's advantageous to do so, such as when it upgrades to a newer version of HTTP.
