code: def insert(self, key, value, ttl=0, format=None, persist_to=0, replicate_to=0):
          
          return _Base.insert(self, key, value, ttl=ttl, format=format,
                              persist_to=persist_to, replicate_to=replicate_to)
docs: Store an object in Couchbase unless it already exists.
  
          Follows the same conventions as :meth:`upsert` but the value is
          stored only if it does not exist already. Conversely, the value
          is not stored if the key already exists.
  
          Notably missing from this method is the `cas` parameter, this is
          because `insert` will only succeed if a key does not already
          exist on the server (and thus can have no CAS)
  
          :raise: :exc:`.KeyExistsError` if the key already exists
  
          .. seealso:: :meth:`upsert`, :meth:`insert_multi`