core-bundle/src/Resources/contao/library/Contao/Template.php
public function flushAllData()
	{
		@trigger_error('Using Template::flushAllData() has been deprecated and will no longer work in Contao 5.0.', E_USER_DEPRECATED);

		if (\function_exists('fastcgi_finish_request'))
		{
			fastcgi_finish_request();
		}
		elseif (PHP_SAPI !== 'cli')
		{
			$status = ob_get_status(true);
			$level = \count($status);

			while ($level-- > 0 && (!empty($status[$level]['del']) || (isset($status[$level]['flags']) && ($status[$level]['flags'] & PHP_OUTPUT_HANDLER_REMOVABLE) && ($status[$level]['flags'] & PHP_OUTPUT_HANDLER_FLUSHABLE))))
			{
				ob_end_flush();
			}

			flush();
		}
	}
public function flushAllData()
	{
		@trigger_error('Using Template::flushAllData() has been deprecated and will no longer work in Contao 5.0.', E_USER_DEPRECATED);

		if (\function_exists('fastcgi_finish_request'))
		{
			fastcgi_finish_request();
		}
		elseif (PHP_SAPI !== 'cli')
		{
			$status = ob_get_status(true);
			$level = \count($status);

			while ($level-- > 0 && (!empty($status[$level]['del']) || (isset($status[$level]['flags']) && ($status[$level]['flags'] & PHP_OUTPUT_HANDLER_REMOVABLE) && ($status[$level]['flags'] & PHP_OUTPUT_HANDLER_FLUSHABLE))))
			{
				ob_end_flush();
			}

			flush();
		}
	}
Flush the output buffers

@deprecated Deprecated since Contao 4.0, to be removed in Contao 5.0.