question: public Options addOption ( Option opt ) { String key = opt . getKey ( ) ; if ( opt . hasLongOpt ( ) ) { longOpts . put ( opt . getLongOpt ( ) , opt ) ; } if ( opt . isRequired ( ) ) { if ( requiredOpts . contains ( key ) ) { requiredOpts . remove ( requiredOpts . indexOf ( key ) ) ; } requiredOpts . add ( key ) ; } shortOpts . put ( key , opt ) ; return this ; }
target:  Adds an option instance