Coerces responses to SpatialPoints, SpatialLines, or SpatialPolygons data frames.
as_sp(geo, ...)# S3 method for geo_list
as_sp(geo, ...)
# S3 method for mapzen_vector_layer
as_sp(geo, ..., geometry_type = NULL)
The object to be converted
not currently used
"point", "line", or "polygon" -- can be left NULL and only needs to be specified when an object contains multiple geometry types.