+ ['a1', 'b1', 'a2', 'b2', 'c1', 'c2', 'a3', 'a4', 'b3', 'c3', 'a5' ],
+ );
+
+ is_deeply(
+ [ _pack_subfields_hash({
+ a => [ 'a1', 'a2' ], b => [ 'b1', 'b2' ], c => [ 'c1', 'c2' ],
+ subfields => [ qw/a 0 b 0 a 1 b 1 c 0 c 1/ ],
+ }) ],
+ ['a1', 'b1', 'a2', 'b2', 'c1', 'c2'],
+ '_pack_subfields_hash( $h )'
+ );
+
+ is_deeply(
+ [ _pack_subfields_hash({
+ a => [ 'a1', 'a2' ], b => [ 'b1', 'b2' ], c => [ 'c1', 'c2' ],
+ subfields => [ qw/a 0 b 0 a 1 b 1 c 0 c 1/ ],
+ }, 1) ],
+ ['^a','a1', '^b','b1', '^a','a2', '^b','b2', '^c','c1', '^c','c2'],
+ '_pack_subfields_hash( $h, 1 )'