Settings::getStoragePid() 

\nn\t3::Settings()->getStoragePid($extName = NULL); 

Get current (FIRST) StoragePid for the current plugin. Saved in the TypoScript setup of the extension under | plugin.tx_extname.persistence.storagePid or in the FlexForm of the plugin on the respective page.

IMPORTANT: Merge with selected StoragePID from the FlexForm only happens if $extNameis left empty.

\nn\t3::Settings()->getStoragePid(); // 123
\nn\t3::Settings()->getStoragePid('nnsite'); // 466

| @return string

public function getStoragePid ( $extName = null )
{
	$pids = $this->getStoragePids( $extName );
	return array_pop( $pids );
}