original_string: public static function primary_key()
  	{
  		$id_only = static::get_primary_key_id_only_status();
  		$pk_status = static::get_primary_key_status();
  
  		if ($id_only)
  		{
  			return static::getNonTimestampPks();
  		}
  
  		if ($pk_status && ! $id_only)
  		{
  			return static::$_primary_key;
  		}
  
  		return array();
  	}
code: public static function primary_key()
  	{
  		$id_only = static::get_primary_key_id_only_status();
  		$pk_status = static::get_primary_key_status();
  
  		if ($id_only)
  		{
  			return static::getNonTimestampPks();
  		}
  
  		if ($pk_status && ! $id_only)
  		{
  			return static::$_primary_key;
  		}
  
  		return array();
  	}
code_tokens: public static function primary_key ( ) { $ id_only = static :: get_primary_key_id_only_status ( ) ; $ pk_status = static :: get_primary_key_status ( ) ; if ( $ id_only ) { return static :: getNonTimestampPks ( ) ; } if ( $ pk_status && ! $ id_only ) { return static :: $ _primary_key ; } return array ( ) ; }
docstring: Overrides the parent primary_key method to allow primaray key enforcement
  to be turned off when updating a temporal model.
docstring_tokens: Overrides the parent primary_key method to allow primaray key enforcement to be turned off when updating a temporal model .