A set of values that specify the quality of the polyline.

POLYLINE_QUALITY_UNSPECIFIED No polyline quality preference specified. Defaults to OVERVIEW.
HIGH_QUALITY Specifies a high-quality polyline - which is composed using more points than OVERVIEW, at the cost of increased response size. Use this value when you need more precision.
OVERVIEW Specifies an overview polyline - which is composed using a small number of points. Use this value when displaying an overview of the route. Using this option has a lower request latency compared to using the HIGH_QUALITY option.