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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_association_to_graph(self):
 """ The reified relationship between a disease and a phenotype is decorated with some provenance information. This makes the assumption that both the disease and phenotype are classes. :param g: :return: """


        # add the basic association nodes
        # if rel == self.globaltt[['has disposition']:

        Assoc.add_association_to_graph(self)
        # anticipating trouble with onsets ranges that look like curies
        if self.onset is not None and self.onset != '':
            self.graph.addTriple(self.assoc_id, self.globaltt['onset'], self.onset)

        if self.frequency is not None and self.frequency != '':
            self.graph.addTriple(
                self.assoc_id, self.globaltt['frequency'], self.frequency)

        return