namespace* -- sets the default XML namespace (for "xmlns")

  *method* -- either "xml" (default), "html, "text", or "c14n"

  *short_empty_elements* -- controls the formatting of elements
                            that contain no content. If True (default)
                            they are emitted as a single self-closed
                            tag, otherwise they are emitted as a pair
                            of start/end tags

