lib/Jejik/MT940/Reader.php
public function setClosingBalanceClass($closingBalanceClass)
    {
        if (!is_callable($closingBalanceClass) && !class_exists($closingBalanceClass)) {
            throw new \InvalidArgumentException('$closingBalanceClass must be a valid classname or a PHP callable');
        }

        $this->closingBalanceClass = $closingBalanceClass;
        return $this;
    }
public function setClosingBalanceClass($closingBalanceClass)
    {
        if (!is_callable($closingBalanceClass) && !class_exists($closingBalanceClass)) {
            throw new \InvalidArgumentException('$closingBalanceClass must be a valid classname or a PHP callable');
        }

        $this->closingBalanceClass = $closingBalanceClass;
        return $this;
    }
Set the classname of the closing balance class or callable that returns an object that
implements the BalanceInterface.

The callable is not passed any arguments.

$reader->setClosingBalanceClass(function () {
return new My\Balance();
});

@param string|callable $closingBalanceClass
@return $this