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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 downstream(self, f, n=1):
 """find n downstream features where downstream is determined by the strand of the query Feature f Overlapping features are not considered. f: a Feature object n: the number of features to return """

        if f.strand == -1:
            return self.left(f, n)
        return self.right(f, n)