Atlas is a Flutter Widget which abstracts the underlying map provider
and exposes a developer-friendly, declarative API for working with a map.
The underlying map provider that will be used must be specified as the
AtlasProvider.instance before the Atlas widget is rendered.
The AtlasProvider maintains the Provider instance that will be used
with the Atlas widget. AtlasProvider is a singleton and should be configured
to use the desired Provider before the Atlas widget is rendered.
The CameraPosition represents the position of the map "camera",
the view point from which the world is shown in the map view.
Aggregates the camera's target geographical location and the its zoom level.
The Provider defines the interface to which all AtlasProviders must conform.
In order to implement a custom AtlasProvider you must simply implement Provider
and set your AtlasProvider.instance to the instance of your custom Provider.
A pair of x and y coordinates.
The x and y coordinates are stored as screen pixels (not display pixels)
relative to the top of the map, not top left of the whole screen.