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

		$this->compile();

		header('Content-Type: ' . $this->strContentType . '; charset=' . Config::get('characterSet'));

		echo $this->strBuffer;

		// Flush the output buffers (see #6962)
		$this->flushAllData();
	}
public function output()
	{
		@trigger_error('Using Template::output() has been deprecated and will no longer work in Contao 5.0. Use Template::getResponse() instead.', E_USER_DEPRECATED);

		$this->compile();

		header('Content-Type: ' . $this->strContentType . '; charset=' . Config::get('characterSet'));

		echo $this->strBuffer;

		// Flush the output buffers (see #6962)
		$this->flushAllData();
	}
Parse the template file and print it to the screen

@deprecated Deprecated since Contao 4.0, to be removed in Contao 5.0.
Use Template::getResponse() instead.