code: function applyOps(data, ops, className) {
    debugPrint('OPS', ops);
    _.forIn(ops, (value, key) => {
      const operator = value.__op;
  
      if (operator in UPDATE_OPERATORS) {
        UPDATE_OPERATORS[operator](data, key, value, className);
      } else {
        throw new Error(`Unknown update operator: ${key}`);
      }
  
      if (MASKED_UPDATE_OPS.has(operator)) {
        getMask(className).add(key);
      }
    });
  }
docs: Destructive. Applies all the update `ops` to `data`. Throws on unknown update operator.