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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 visit_yieldfrom(self, node):
 """ Return an astroid.YieldFrom node as string. """

        yi_val = (" " + node.value.accept(self)) if node.value else ""
        expr = "yield from" + yi_val
        if node.parent.is_statement:
            return expr

        return "(%s)" % (expr,)