code: public static function setCookie($strKey, $varValue)
  	{
  		$strKey = static::cleanKey($strKey);
  
  		unset(static::$arrCache['cookieEncoded'][$strKey]);
  		unset(static::$arrCache['cookieDecoded'][$strKey]);
  
  		if ($varValue === null)
  		{
  			unset($_COOKIE[$strKey]);
  		}
  		else
  		{
  			$_COOKIE[$strKey] = $varValue;
  		}
  	}
docs: Set a $_COOKIE variable
  
  @param string $strKey   The variable name
  @param mixed  $varValue The variable value