public function polyline(array $coordinates = [], array $options = [])
	{
		$items = $this->getItems();

		if (empty($items)) {
			throw new MapperInstanceException('No map found to add a polyline to.');
		}

		$defaults = [
			'coordinates' => $coordinates,
			'geodesic' => false,
			'strokeColor' => '#FF0000',
			'strokeOpacity' => 0.8,
			'strokeWeight' => 2,
			'editable' => false
		];

		$item = end($items);
		$options = array_replace_recursive(
			$defaults,
			$options
		);

		$item->shape('polyline', $coordinates, $options);

		return $this;
	}