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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 stations(self, *stns):
 """Specify one or more stations for the query. This modifies the query in-place, but returns `self` so that multiple queries can be chained together on one line. This replaces any existing spatial queries that have been set. Parameters stns : one or more strings One or more names of variables to request Returns ------- self : RadarQuery Returns self for chaining calls """

        self._set_query(self.spatial_query, stn=stns)
        return self