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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 contains(self, assertion):
 """ Returns `True` if `assertion` is contained in this `Independencies`-object, otherwise `False`. Parameters assertion: IndependenceAssertion()-object Examples -------- True True False """

        if not isinstance(assertion, IndependenceAssertion):
            raise TypeError("' in <Independencies()>' requires IndependenceAssertion" +
                            " as left operand, not {0}".format(type(assertion)))

        return assertion in self.get_assertions()