public function checkUserIsACollaborator(string $username): bool
    {
        $this->getApi()->request($this->getApi()->sprintf('/repos/:owner/:repo/collaborators/:username',
            $this->getRepositories()->getOwner(), $this->getRepositories()->getRepo(), $username));

        if ($this->getApi()->getHeaders()['Status'] == '204 No Content') {
            return true;
        }

        return false;
    }