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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 full_name(self):
 """Returns the full name of this element by visiting every non-None parent in its ancestor chain."""

        if self._full_name is None:
            ancestors = [ self.name ]
            current = self.parent
            while current is not None and type(current).__name__ != "CodeParser":
                ancestors.append(current.name)
                current = current.parent

            self._full_name = ".".join(reversed(ancestors))
        
        return self._full_name