283 #1

use Test;

my &uniq = *.Bag.first(*.value == 1).key;

is (3, 3, 1).&uniq, 1;
is (3, 2, 4, 2, 4).&uniq, 3;
is (1).&uniq, 1;
is (4, 3, 1, 1, 1, 4).&uniq, 3;