system/CodeIgniter.php
public function cachePage(Cache $config)
	{
		$headers = [];
		foreach ($this->response->getHeaders() as $header)
		{
			$headers[$header->getName()] = $header->getValueLine();
		}

		return cache()->save(
						$this->generateCacheName($config), serialize(['headers' => $headers, 'output' => $this->output]), static::$cacheTTL
		);
	}
public function cachePage(Cache $config)
	{
		$headers = [];
		foreach ($this->response->getHeaders() as $header)
		{
			$headers[$header->getName()] = $header->getValueLine();
		}

		return cache()->save(
						$this->generateCacheName($config), serialize(['headers' => $headers, 'output' => $this->output]), static::$cacheTTL
		);
	}
Caches the full response from the current request. Used for
full-page caching for very high performance.

@param \Config\Cache $config

@return mixed