function baseUpdate(object, path, updater, customizer) {
      return baseSet(object, path, updater(baseGet(object, path)), customizer);
    }
The base implementation of `_.update`.

@private
@param {Object} object The object to modify.
@param {Array|string} path The path of the property to update.
@param {Function} updater The function to produce the updated value.
@param {Function} [customizer] The function to customize path creation.
@returns {Object} Returns `object`.