Task/Database/DatabaseReaderTask.php
public function next(ProcessState $state)
    {
        if (!$this->statement) {
            return false;
        }

        $this->nextItem = $this->statement->fetch();

        return (bool) $this->nextItem;
    }
public function next(ProcessState $state)
    {
        if (!$this->statement) {
            return false;
        }

        $this->nextItem = $this->statement->fetch();

        return (bool) $this->nextItem;
    }
Moves the internal pointer to the next element,
return true if the task has a next element
return false if the task has terminated it's iteration

@param ProcessState $state

@throws \LogicException

@return bool