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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 get_report(self):
 """ describe the graph :returns: report :rtype: string """

    ostr = ''
    ostr += "Nodes: "+str(len(self.__nodes.keys()))+"\n"
    ostr += "Edges: "+str(len(self.__edges.keys()))+"\n"
    return ostr