Service/CustomFieldsHelper.php
private function _cacheCustomFieldsGroup(CustomFieldsGroup $group)
    {
        foreach ($group->getCustomFields() as $field) {
            $this->cache[$group->getEntity()][$field->getSlug()] = $field;
        }
    }
private function _cacheCustomFieldsGroup(CustomFieldsGroup $group)
    {
        foreach ($group->getCustomFields() as $field) {
            $this->cache[$group->getEntity()][$field->getSlug()] = $field;
        }
    }
Set in cache of the custom fields of a customfield Group.

@param CustomFieldsGroup $group The given CustomFieldsGroup