public function create($owner, $repo, $tree, $base_tree = '')
	{
		// Build the request path.
		$path = '/repos/' . $owner . '/' . $repo . '/git/trees';

		$data = array();

		$data['tree'] = $tree;

		if ($base_tree)
		{
			$data['base_tree'] = $base_tree;
		}

		return $this->processResponse(
			$this->client->post($this->fetchUrl($path), json_encode($data)),
			201
		);
	}