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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def create_from_position(cls, skydir, config, **kwargs):
 """Create an ROIModel instance centered on a sky direction. Parameters skydir : `~astropy.coordinates.SkyCoord` Sky direction on which the ROI will be centered. config : dict Model configuration dictionary. """


        coordsys = kwargs.pop('coordsys', 'CEL')
        roi = cls(config, skydir=skydir, coordsys=coordsys, **kwargs)
        return roi