code: func removeBackendDuplicates(items []backend.Item) []backend.Item {
  	// Use map to record duplicates as we find them.
  	encountered := map[string]bool{}
  	result := make([]backend.Item, 0, len(items))
  
  	// Loop over all items, if it has not been seen before, append to result.
  	for _, e := range items {
  		_, ok := encountered[string(e.Key)]
  		if !ok {
  			// Record this element as an encountered element.
  			encountered[string(e.Key)] = true
  
  			// Append to result slice.
  			result = append(result, e)
  		}
  	}
  
  	return result
  }
docs: // removeDuplicates removes any duplicate items from the passed in slice. This
  // is to ensure that partial matches don't result in multiple values returned.
  // This is consistent with our DynamoDB implementation.