docs: private Map<String, Object> mapMeta(JsonNode metaNode) {
  		JsonParser p = objectMapper.treeAsTokens(metaNode);
  		MapType mapType = TypeFactory.defaultInstance()
  				.constructMapType(HashMap.class, String.class, Object.class);
  		try {
  			return objectMapper.readValue(p, mapType);
  		} catch (IOException e) {
  			// TODO: log? No recovery.
  		}
  
  		return null;
  	}