static _merge(options = {}, addons = {}) {
    /* eslint-disable consistent-return */
    const customizer = (objValue, srcValue) => {
      if (_.isArray(objValue)) {
        return objValue.concat(srcValue);
      }
    };

    return _.mergeWith(_.cloneDeep(addons), options, customizer);
  }
merged inline and rcfile options
  addons has a lower priority
  if the value type is array, the values will concat
  if the value type is object, the values will be merged
merged
@param options
@param addons
@private