src/Composer/Repository/Vcs/GitHubDriver.php
public function getFileContent($file, $identifier)
    {
        if ($this->gitDriver) {
            return $this->gitDriver->getFileContent($file, $identifier);
        }

        $resource = $this->getApiUrl() . '/repos/'.$this->owner.'/'.$this->repository.'/contents/' . $file . '?ref='.urlencode($identifier);
        $resource = JsonFile::parseJson($this->getContents($resource));
        if (empty($resource['content']) || $resource['encoding'] !== 'base64' || !($content = base64_decode($resource['content']))) {
            throw new \RuntimeException('Could not retrieve ' . $file . ' for '.$identifier);
        }

        return $content;
    }
public function getFileContent($file, $identifier)
    {
        if ($this->gitDriver) {
            return $this->gitDriver->getFileContent($file, $identifier);
        }

        $resource = $this->getApiUrl() . '/repos/'.$this->owner.'/'.$this->repository.'/contents/' . $file . '?ref='.urlencode($identifier);
        $resource = JsonFile::parseJson($this->getContents($resource));
        if (empty($resource['content']) || $resource['encoding'] !== 'base64' || !($content = base64_decode($resource['content']))) {
            throw new \RuntimeException('Could not retrieve ' . $file . ' for '.$identifier);
        }

        return $content;
    }
{@inheritdoc}