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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 add_to_subset(self, id, s):
 """ Adds a node to a subset """

        n = self.node(id)
        if 'meta' not in n:
            n['meta'] = {}
        meta = n['meta']
        if 'subsets' not in meta:
            meta['subsets'] = []
        meta['subsets'].append(s)