SolrException: HTTP code=400, reason=Bad Request
  File "indexing.py", line 200, in send_data_to_solr
    solr_connection.add_many(data)
  File "solr/core.py", line 326, in wrapper
    return self._update(content, query)
  File "solr/core.py", line 551, in _update
    rsp = self._post(selector, request, self.xmlheaders)
  File "solr/core.py", line 640, in _post
    return check_response_status(self.conn.getresponse())
  File "solr/core.py", line 1103, in check_response_status
    raise ex

SolrException: HTTP code=400, reason=Bad Request