Match concept
Attempt Match with id attemptId, sourceId alice and targetId ben
Withdraw Attempt attemptId
Show Attempt attemptId
Attempt Match with sourceId ben and targetId alice
Show Match between alice and ben
Show Match between ben and alice
Show Matches
Show Matches with alice
Show All Attempts
Show Attempts by alice
Show Attempts with alice
Show Attempts between alice and ben
Create Match with id matchId, userIds ben and carol
Show Match matchId
Delete Match with id matchId