code: @Override
  	public Map<String, String> toProperties() {
  		DescriptorProperties properties = new DescriptorProperties();
  		List<Map<String, String>> subKeyValues = new ArrayList<>();
  		for (Map.Entry<String, LinkedHashMap<String, String>> entry : tableSchema.entrySet()) {
  			String name = entry.getKey();
  			LinkedHashMap<String, String> props = entry.getValue();
  			Map<String, String> map = new HashMap<>();
  			map.put(SCHEMA_NAME, name);
  			map.putAll(props);
  			subKeyValues.add(map);
  		}
  		properties.putIndexedVariableProperties(
  			SCHEMA,
  			subKeyValues);
  		return properties.asMap();
  	}
docs: Converts this descriptor into a set of properties.