question: public static void registerProtocol ( final String id , final Protocol protocol ) { if ( id == null ) { throw new IllegalArgumentException ( "id is null" ) ; } if ( protocol == null ) { throw new IllegalArgumentException ( "protocol is null" ) ; } PROTOCOLS . put ( id , protocol ) ; }
target:  Registers a new protocol with the given identifier. If a protocol with the given ID already exists it will be overridden. This ID is the same one used to retrieve the protocol from getProtocol(String).