ligo/src/bin_client/test/contracts/vote_for_delegate.tz

parameter (option key_hash) ;
storage (pair
           (pair %mgr1 (address %addr) (option key_hash))
           (pair %mgr2 (address %addr) (option key_hash))) ;
code { # Update the storage
       DUP ; CDAAR %addr @%; SOURCE ; PAIR %@ %@; UNPAIR;
       IFCMPEQ
         { UNPAIR ; SWAP ; SET_CADR }
         { DUP ; CDDAR ; SOURCE ;
           IFCMPEQ
             { UNPAIR ; SWAP ; SET_CDDR }
             { FAIL } } ;
       # Now compare the proposals
       DUP ; CADR ;
       DIP { DUP ; CDDR } ;
       IF_NONE
         { IF_NONE
             { NONE key_hash ;
               SET_DELEGATE ; NIL operation ; SWAP ; CONS }
             { DROP ; NIL operation } }
         { SWAP ;
           IF_SOME
             { DIP { DUP } ;
               IFCMPEQ
                 { SOME ;
                   SET_DELEGATE ; NIL operation ; SWAP ; CONS }
                 { DROP ;
                   NIL operation }}
             { DROP ; NIL operation }} ;
       PAIR }