'Actually send an SDF to CloudSearch for processing
If an SDF file has been explicitly loaded it will be used. Otherwise,
documents added through :func:`add` and :func:`delete` will be used.
:rtype: :class:`CommitResponse`
:returns: A summary of documents added and deleted'

def commit(self):

    sdf = self.get_sdf()
    if (':    null' in sdf):
        boto.log.error('null    value    in    sdf    detected.        This    will    probably    raise    500    error.')
        index = sdf.index(':    null')
        boto.log.error(sdf[(index - 100):(index + 100)])
    url = ('http://%s/2011-02-01/documents/batch' % self.endpoint)
    session = requests.Session()
    adapter = requests.adapters.HTTPAdapter(pool_connections=20, pool_maxsize=50, max_retries=5)
    session.mount('http://', adapter)
    session.mount('https://', adapter)
    r = session.post(url, data=sdf, headers={'Content-Type': 'application/json'})
    return CommitResponse(r, self, sdf)
