+STR
+DOC
+SEQ
=VAL :a?string
=VAL :another ? string
+MAP
=VAL :key
=VAL :value?
-MAP
+SEQ
=VAL :a?string
-SEQ
+SEQ
=VAL :another ? string
-SEQ
+MAP
=VAL :key
=VAL :value?
-MAP
+MAP
=VAL :key
=VAL :value?
-MAP
+MAP
=VAL :key?
=VAL :value
-MAP
-SEQ
-DOC
-STR