/**
  * @param string[] $eans
  * @param array $fields
  *
  * @return $this
  */
 public function fetchProductsByEans(array $eans, array $fields = array())
 {
     $this->query[] = array('products_eans' => array('eans' => $eans, 'fields' => ProductFields::filterFields($fields)));
     return $this;
 }
 /**
  * @param string[] $fields
  *
  * @return $this
  */
 public function selectProductFields(array $fields)
 {
     $this->result['fields'] = ProductFields::filterFields($fields);
     return $this;
 }