question: public boolean deleteOwner ( Principal caller , Principal owner ) throws NotOwnerException , LastOwnerException { if ( ! ownerList . contains ( caller ) ) throw new NotOwnerException ( ) ; if ( ! ownerList . contains ( owner ) ) { return false ; } else { if ( ownerList . size ( ) == 1 ) throw new LastOwnerException ( ) ; ownerList . removeElement ( owner ) ; return true ; } }
target:  Deletes an owner. If this is the last owner in the ACL, an exception is raised. <P> The caller principal must be an owner of the ACL in order to invoke this method.