Eloquent\Phony\Spy\TraversableSpy::valid PHP Метод

    public function valid()
    {
        if (!$this->isUsed) {
            $this->call->addIterableEvent($this->callEventFactory->createUsed());
            if ($this->traversable instanceof IteratorAggregate) {
                $this->iterator = $this->traversable->getIterator();
            } else {
                $this->iterator = $this->traversable;
            }
            $this->isUsed = true;
        }
        if ($isValid = $this->iterator->valid()) {
            $this->key = $this->iterator->key();
            $this->value = $this->iterator->current();
        } else {
            $this->key = null;
            $this->value = null;
        }
        if ($this->isConsumed) {
            return $isValid;
        }
        if ($isValid) {
            $this->call->addIterableEvent($this->callEventFactory->createProduced($this->key, $this->value));
        } else {
            $this->call->setEndEvent($this->callEventFactory->createConsumed());
            $this->isConsumed = true;
        }
        return $isValid;
    }