/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/ is in libservlet3.1-java-doc 8.0.32-1ubuntu1.
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/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/HandshakeRequest.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/PathParam.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/ServerApplicationConfig.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/ServerContainer.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/ServerEndpoint.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/ServerEndpointConfig.Builder.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/ServerEndpointConfig.Configurator.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/ServerEndpointConfig.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/package-frame.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/package-summary.html
/usr/share/doc/libservlet3.1-java/api/javax/websocket/server/package-tree.html