Cake\ORM\Table::aliasField PHP Method

    public function aliasField($field)
    {
        if (strpos($field, '.') !== false) {
            return $field;
        }
        return $this->alias() . '.' . $field;
    }

 /**
  * Callback method that listens to the `beforeFind` event in the bound
  * table. It modifies the passed query by eager loading the translated fields
  * and adding a formatter to copy the values into the main table records.
  *
  * @param \Cake\Event\Event $event The beforeFind event that was fired.
  * @param \Cake\ORM\Query $query Query
  * @param \ArrayObject $options The options for the query
  * @return void
  */
 public function beforeFind(Event $event, Query $query, $options)
 {
     $locale = $this->locale();
     if ($locale === $this->config('defaultLocale')) {
         return;
     }
     $conditions = function ($field, $locale, $query, $select) {
         return function ($q) use($field, $locale, $query, $select) {
             $q->where([$q->repository()->aliasField('locale') => $locale]);
             if ($query->autoFields() || in_array($field, $select, true) || in_array($this->_table->aliasField($field), $select, true)) {
                 $q->select(['id', 'content']);
             }
             return $q;
         };
     };
     $contain = [];
     $fields = $this->_config['fields'];
     $alias = $this->_table->alias();
     $select = $query->clause('select');
     $changeFilter = isset($options['filterByCurrentLocale']) && $options['filterByCurrentLocale'] !== $this->_config['onlyTranslated'];
     foreach ($fields as $field) {
         $name = $alias . '_' . $field . '_translation';
         $contain[$name]['queryBuilder'] = $conditions($field, $locale, $query, $select);
         if ($changeFilter) {
             $filter = $options['filterByCurrentLocale'] ? 'INNER' : 'LEFT';
             $contain[$name]['joinType'] = $filter;
         }
     }
     $query->contain($contain);
     $query->formatResults(function ($results) use($locale) {
         return $this->_rowMapper($results, $locale);
     }, $query::PREPEND);
 }