human
I wrote the below code

    INDENT = ('    ' * indent_width)
    def _prettify(elem, indent_level=0):
        if elem:
            elem.text = ('\n' + (INDENT * (indent_level + 1)))
            for child in elem:
                _prettify(child, (indent_level + 1))
            elem[(-1)].tail = ('\n' + (INDENT * indent_level))
            elem.tail = ('\n' + (INDENT * indent_level))
        else:
            elem.text = None
            elem.tail = ('\n' + (INDENT * indent_level))
    _prettify(tree)
    return tree

What's a good function header?
 ... Here's a good function header?
assistant
#Here's a good function header.

def pretty_tree_from_tree(tree, indent_width=2):