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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 list(self, out=sys.stdout):
 """ Prints a listing of the properties to the stream 'out' which defaults to the standard output """


        out.write('-- listing properties --\n')
        for key,value in self._properties.items():
            out.write(''.join((key,'=',value,'\n')))