Go\Instrument\Transformer\CachingTransformer::processTransformers PHP Method

    private function processTransformers(StreamMetaData $metadata)
    {
        if (is_callable($this->transformers)) {
            $delayedTransformers = $this->transformers;
            $this->transformers = $delayedTransformers();
        }
        foreach ($this->transformers as $transformer) {
            $isTransformed = $transformer->transform($metadata);
            // transformer reported about termination, next transformers will be skipped
            if ($isTransformed === false) {
                return false;
            }
        }
        return true;
    }