'Retrieve file data from the Key, and return contents as a string.
:type headers: dict
:param headers: ignored in this subclass.
:type cb: function
:param cb: ignored in this subclass.
:type cb: int
:param num_cb: ignored in this subclass.
:type cb: int
:param num_cb: ignored in this subclass.
:type torrent: bool
:param torrent: ignored in this subclass.
:rtype: string
:returns: The contents of the file as a string'

def get_contents_as_string(self, headers=None, cb=None, num_cb=10, torrent=False):

    fp = StringIO()
    self.get_contents_to_file(fp)
    return fp.getvalue()
