code: public static Map<String, Object> bodyOfSelectedRevision(Document doc) {
          byte[] body;
          try {
              body = doc.getSelectedBody();
          } catch (ForestException e) {
              return null;
          }
          Map<String, Object> properties = null;
          if (body != null && body.length > 0) {
              try {
                  properties = Manager.getObjectMapper().readValue(body, Map.class);
              } catch (IOException e) {
                  Log.w(TAG, "Failed to parse body: [%s]", new String(body));
              }
          }
          return properties;
      }
docs: in CBLForestBridge.m
  + (BOOL) loadBodyOfRevisionObject: (CBL_MutableRevision*)rev
  doc: (VersionedDocument&)doc