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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 _call(self, x, out=None):
 """Return the zero vector or assign it to ``out``."""

        if self.domain == self.range:
            if out is None:
                out = 0 * x
            else:
                out.lincomb(0, x)
        else:
            result = self.range.zero()
            if out is None:
                out = result
            else:
                out.assign(result)
        return out