e the parsed contents of a python function.

    Children::

        0. <Keyword: def>
        1. <Name>
        2. parameter list (including open-paren and close-paren <Operator>s)
        3. or 5. <Operator: :>
        4. or 6. Node() representing function body
        3. -> (if annotation is also present)
        4. annotation (if present)
    r