code: private function mergeAttribute($attributes, $raw)
      {
          $parts                   = explode('=', $raw);
          list($name, $value)      = count($parts) === 1 ? array($parts[0], $parts[0]) : $parts;
          $attributes[trim($name)] = html_entity_decode($this->dequote(trim($value)), ENT_QUOTES);
  
          return $attributes;
      }
docs: Overlay an attribute into the attributes hash.
  
  @param array $attributes        Current attribute list.
  @param string $raw              Raw attribute string with both key and value.
  
  @return array                   New attribute hash.