initializing libraries and imports.

[MahaAdel]

I dont get where should I put this
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4.Initialize the StaticMapProvider
var provider = new StaticMapProvider('your_api_key');
5.The StaticMapProvider offers a few different APIs for generating static maps. If you want to generate an image for the current viewport of your full screen interactive map you can use:
var uri = staticMapProvider.getImageUriFromMap(mapView,
width: 900, height: 400);)