code: func (s *CombinedPrimitiveSlice) UpsertLocal(l interface{}) {
  	v := s.upsert(l)
  	v.local = l
  	v.localSet = true
  }
docs: // UpsertLocal adds l to the slice.  If there is already a value of l in the
  // slice for either the recorded or remote, set on that value as the local value
  // Otherwise append a new item to the list with the local value.