code: protected function getValue($field)
      {
          $getter = $method = AccessorUtil::getter($field);
  
          if (!method_exists($this->object, $getter)) {
              $isser = $method = AccessorUtil::isser($field);
  
              if (!method_exists($this->object, $isser)) {
                  throw new BadGetterException('Getter %s or %s for object does not exists', $getter, $isser);
              }
          }
  
          return $this->object->{$method}();
      }
docs: @param string $field
  
  @return mixed
  @throws BadGetterException