':return: A verbose string representation of the ``DependencySpan``.
:rtype: str'

def __str__(self):

    str = (u'Span    %d-%d;    Head    Index:    %d' % (self._start_index, self._end_index, self._head_index))
    for i in range(len(self._arcs)):
        str += (u'\n%d    <-    %d,    %s' % (i, self._arcs[i], self._tags[i]))
    return str
