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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 addSourceGroup(self, sourceGroupUri, weight):
 """ add a list of relevant sources by specifying a whole source group to the topic page @param sourceGroupUri: uri of the source group to add @param weight: importance of the provided list of sources (typically in range 1 - 50) """

        assert isinstance(weight, (float, int)), "weight value has to be a positive or negative integer"
        self.topicPage["sourceGroups"].append({"uri": sourceGroupUri, "wgt": weight})