+STR
+DOC
+MAP
=VAL "value
=VAL "100
=VAL "next_foo
+MAP
=VAL "value
=VAL "101
=VAL "next_foo
+MAP
=VAL "value
=VAL "102
=VAL "next_foo
=VAL "null
-MAP
-MAP
-MAP
-DOC
-STR