code: func indexTableSchema() *memdb.TableSchema {
  	return &memdb.TableSchema{
  		Name: "index",
  		Indexes: map[string]*memdb.IndexSchema{
  			"id": &memdb.IndexSchema{
  				Name:         "id",
  				AllowMissing: false,
  				Unique:       true,
  				Indexer: &memdb.StringFieldIndex{
  					Field:     "Key",
  					Lowercase: true,
  				},
  			},
  		},
  	}
  }
docs: // indexTableSchema returns a new table schema used for tracking various indexes
  // for the Raft log.