def add_exp2(self, name, input_name, output_name):
        """
        Add an exp2 layer to the model that performs element-wise experiential operation.
        Refer to the ``Exp2LayerParams`` message in the specification (NeuralNetwork.proto) for more details.

        Parameters
        ----------
        name: str
            The name of this layer.
        input_name: str
            The input blob name of this layer.
        output_name: str
            The output blob name of this layer.
        """

        spec_layer = self._add_generic_layer(name, [input_name], [output_name])
        spec_layer.exp2.MergeFromString(b"")
        return spec_layer

        Add an exp2 layer to the model that performs element-wise experiential operation.
        Refer to the ``Exp2LayerParams`` message in the specification (NeuralNetwork.proto) for more details.

        Parameters
        ----------
        name: str
            The name of this layer.
        input_name: str
            The input blob name of this layer.
        output_name: str
            The output blob name of this layer.
        
coremltools/models/neural_network/builder.py