'Returns a dict in which the keys are the HTML data attributes
to set on the annotation element. Each data attribute has a
corresponding \'value\' and (optional) \'_delete\' key to specify
an XML attribute to delete.'

def _get_annotation_data_attr(self, index, el):

    data_attrs = {}
    attrs_map = {'body': 'data-comment-body', 'title': 'data-comment-title', 'problem': 'data-problem-id'}
    for xml_key in attrs_map.keys():
        if (xml_key in el.attrib):
            value = el.get(xml_key, '')
            html_key = attrs_map[xml_key]
            data_attrs[html_key] = {'value': value, '_delete': xml_key}
    return data_attrs
