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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 _get_controller_type(self):
 """Returns the current node's controller type"""


        if self.node_type == self.NODE_CONTROLLER_ROOT and self.name in self.CONTROLLERS:
            return self.name
        elif self.parent:
            return self.parent.controller_type
        else:
            return None