calibrate image map

[Thord82]

Hello, thank you very much for creating this package. I would like to ask a question, I am currently using a custom image as a map, and I would like to know how I could calibrate it, that is, for example, that its upper right corner be (10,10) and the lower left corner (-10,-10). I have reviewed the loadMap class, basemap ect, and I have not found something to be able to set. Thank you so much.