'Initialize a new Element wrapper for ``etree``.
If ``etree`` is a string, then it will be converted to an
Element object using ``ElementTree.fromstring()`` first:
>>> ElementWrapper("<test></test>")
<Element "<?xml version=\'1.0\' encoding=\'utf8\'?>\n<test />">'

def __init__(self, etree):

    if isinstance(etree, string_types):
        etree = ElementTree.fromstring(etree)
    self.__dict__['_etree'] = etree
