void displayMap(RectangleGeographicArea initialViewport,
Requests a map service provider to display a map. An application may specify a set geographical areas, a set of landmarks, a coordinates object and a route to be shown on the map. An application may request only one of these alternatives or any combination of them. The application also specifies what is the initial viewport to the map that is shown to the user with Viewport object. Passing null as the initial viewport, means that the map service provider decides the initial viewport.