def configure(self, in_obj):
        if hasattr(self, 'in_shape') and in_obj is None:
            return self  # previously configured, so just return
        super(BranchNode, self).configure(in_obj)
        self.out_shape = self.in_shape
        return self
sets shape based parameters of this layer given an input tuple or int
dataset/ETHPy150Open NervanaSystems/neon/neon/layers/layer.py/BranchNode.configure