/** * Select a protocol version from the list. Called from ServerHandshaker to negotiate protocol * version. * * <p>Return the lower of the protocol version suggested in the clien hello and the highest * supported by the server. */ ProtocolVersion selectProtocolVersion(ProtocolVersion protocolVersion) { if (activeProtocols == null) { activeProtocols = getActiveProtocols(); } return activeProtocols.selectProtocolVersion(protocolVersion); }