docs: function(metaFields, json_in, data_out) {
          if (isObject(metaFields)) {
              var key, path;
              for(key in metaFields) {
                  if (metaFields.hasOwnProperty(key)) {
                      path = SchemaJSON.getPath(metaFields[key]);
                      if (path && json_in) {
                          data_out.meta[key] = SchemaJSON.getLocationValue(path, json_in);
                      }
                  }
              }
          }
          else {
              data_out.error = new Error("JSON meta data retrieval failure");
          }
          return data_out;
      }