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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_source(cls, name, config, **kwargs):
 """Create an ROI centered on the given source."""


        coordsys = kwargs.pop('coordsys', 'CEL')

        roi = cls(config, src_radius=None, src_roiwidth=None,
                  srcname=name, **kwargs)
        src = roi.get_source_by_name(name)

        return cls.create_from_position(src.skydir, config,
                                        coordsys=coordsys, **kwargs)