core-bundle/src/Resources/contao/library/Contao/Session.php
public function setData($arrData)
	{
		if (!\is_array($arrData))
		{
			throw new \Exception('Array required to set session data');
		}

		// Map the referer (see #281)
		foreach ($this->mappedKeys as $strKey)
		{
			if (isset($arrData[$strKey]))
			{
				$this->session->set($strKey, $arrData[$strKey]);
				unset($arrData[$strKey]);
			}
		}

		$this->sessionBag->replace($arrData);
	}
public function setData($arrData)
	{
		if (!\is_array($arrData))
		{
			throw new \Exception('Array required to set session data');
		}

		// Map the referer (see #281)
		foreach ($this->mappedKeys as $strKey)
		{
			if (isset($arrData[$strKey]))
			{
				$this->session->set($strKey, $arrData[$strKey]);
				unset($arrData[$strKey]);
			}
		}

		$this->sessionBag->replace($arrData);
	}
Set the session data from an array

@param array $arrData The session data

@throws \Exception If $arrData is not an array