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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_properties(self):
 """ Add property to variables in BIF Returns ------- dict: dict of type {variable: list of properties } Example ------- {'bowel-problem': ['position = (335, 99)'], 'dog-out': ['position = (300, 195)'], 'family-out': ['position = (257, 99)'], 'hear-bark': ['position = (296, 268)'], 'light-on': ['position = (218, 195)']} """

        variables = self.model.nodes()
        property_tag = {}
        for variable in sorted(variables):
            properties = self.model.node[variable]
            properties = collections.OrderedDict(sorted(properties.items()))
            property_tag[variable] = []
            for prop, val in properties.items():
                property_tag[variable].append(str(prop) + " = " + str(val))
        return property_tag