'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)])
    api_version = '2013-01-01'
    if (self.domain and self.domain.layer1):
        api_version = self.domain.layer1.APIVersion
    if self.sign_request:
        r = self._commit_with_auth(sdf, api_version)
    else:
        r = self._commit_without_auth(sdf, api_version)
    return CommitResponse(r, self, sdf, signed_request=self.sign_request)
