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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 filter(self, fn, skip_na=True, seed=None):
 """ Filter this SArray by a function. Returns a new SArray filtered by this SArray. If `fn` evaluates an element to true, this element is copied to the new SArray. If not, it isn't. Throws an exception if the return type of `fn` is not castable to a boolean value. Parameters fn : function Function that filters the SArray. Must evaluate to bool or int. skip_na : bool, optional If True, will not apply fn to any undefined values. seed : int, optional Used as the seed if a random number generator is included in fn. Returns ------- out : SArray The SArray filtered by fn. Each element of the SArray is of type int. Examples -------- dtype: int Rows: 2 [1, 2] """

        assert callable(fn), "Input must be callable"
        if seed is None:
            seed = abs(hash("%0.20f" % time.time())) % (2 ** 31)


        with cython_context():
            return SArray(_proxy=self.__proxy__.filter(fn, skip_na, seed))