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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 add_to_parent(self):
 """Adds this node to the parent's ``children`` collection if it exists."""

        parent = self.parent
        if parent is not None:
            try:
                children = parent.children
            except AttributeError: pass
            else:
                include(children, self)