Neos\Flow\Persistence\Generic\Query::isEmpty PHP Method

    public function isEmpty($propertyName)
    {
        if (!$this->classSchema->isMultiValuedProperty($propertyName)) {
            throw new InvalidQueryException('Property "' . $propertyName . '" must be multi-valued', 1276853547);
        }
        return $this->qomFactory->comparison($this->qomFactory->propertyValue($propertyName, '_entity'), QueryInterface::OPERATOR_IS_EMPTY);
    }