'Initial setup for in-place document transforms.'

def __init__(self, document, startnode=None):

    self.document = document
    'The    document    tree    to    transform.'
    self.startnode = startnode
    'Node    from    which    to    begin    the    transform.        For    many    transforms    which\n                                apply    to    the    document    as    a    whole,    `startnode`    is    not    set    (i.e.    its\n                                value    is    `None`).'
    self.language = languages.get_language(document.settings.language_code)
    'Language    module    local    to    this    document.'
