A case class which represents Geometry with an SRID.
val projected = Point(1,1).withSRID(4326) // LatLng, trust me
val projected = projected.reproject(LatLng, WebMercator)(3857)
This exists because PostGIS requires an SRID to be stored
with the Geometry and the decision has been made not to encapsulate
SRID semantics in the Geometry hierarchy for the moment.
It is up to the application developer to ensure that
the SRID parameter stays semantically consistent.