What would it take to support multiple inputs from a set of inputs?

[johnsrude]

graph.py states

    # A note on layers and outputs:
    # In Caffe, each layer can produce multiple outputs ("tops") from a set of inputs
    # ("bottoms"). The bottoms refer to other layers' tops. The top can rewrite a bottom
    # (in case of in-place operations). Note that the layer's name is not used for establishing
    # any connectivity. It's only used for data association. By convention, a layer with a
    # single top will often use the same name (although this is not required).
    #
    # The current implementation only supports single-output nodes (note that a node can still
    # have multiple children, since multiple child nodes can refer to the single top's name).

What would need to be done to add support for multiple-output nodes?