Perform a single insert operation.

            {'docid': ObjectId('4e95ae77a20e6164850761cd'),
             'ns': u'mydb.tweets',
             'raw': {u'h': -1469300750073380169L,
                     u'ns': u'mydb.tweets',
                     u'o': {u'_id': ObjectId('4e95ae77a20e6164850761cd'),
                            u'content': u'Lorem ipsum',
                            u'nr': 16},
                     u'op': u'i',
                     u'ts': Timestamp(1318432375, 1)}}

def insert(self, ns, docid, raw, **kw):
        """ Perform a single insert operation.

            {'docid': ObjectId('4e95ae77a20e6164850761cd'),
             'ns': u'mydb.tweets',
             'raw': {u'h': -1469300750073380169L,
                     u'ns': u'mydb.tweets',
                     u'o': {u'_id': ObjectId('4e95ae77a20e6164850761cd'),
                            u'content': u'Lorem ipsum',
                            u'nr': 16},
                     u'op': u'i',
                     u'ts': Timestamp(1318432375, 1)}}
        """
        try:
            self._dest_coll(ns).insert(raw['o'], safe=True)
        except DuplicateKeyError, e:
            logging.warning(e)