+STR
+DOC ---
+MAP
=VAL :nested sequences
+SEQ
+SEQ
+SEQ
+SEQ
-SEQ
-SEQ
-SEQ
+SEQ
+SEQ
+MAP
-MAP
-SEQ
-SEQ
-SEQ
=VAL :key1
+SEQ
-SEQ
=VAL :key2
+MAP
-MAP
-MAP
-DOC
-STR