public function keyUsage(): Ext\KeyUsageExtension
    {
        /** @var Extension\KeyUsageExtension $keyUsage */
        $keyUsage = $this->get(Ext\Extension::OID_KEY_USAGE);
        return $keyUsage;
    }
public function keyUsage(): Ext\KeyUsageExtension
    {
        /** @var Extension\KeyUsageExtension $keyUsage */
        $keyUsage = $this->get(Ext\Extension::OID_KEY_USAGE);
        return $keyUsage;
    }
public function keyUsage ( ) : Ext \ KeyUsageExtension { /** @var Extension\KeyUsageExtension $keyUsage */ $ keyUsage = $ this -> get ( Ext \ Extension :: OID_KEY_USAGE ) ; return $ keyUsage ; }
Get 'Key Usage' extension.

@throws \LogicException If extension is not present
@return \X509\Certificate\Extension\KeyUsageExtension
Get Key Usage extension .