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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 to_json_object(self):
 """Returns a dict representation that can be serialized to JSON."""

    obj_dict = dict(namespace_start=self.namespace_start,
                    namespace_end=self.namespace_end)
    if self.app is not None:
      obj_dict['app'] = self.app
    return obj_dict