index property
Index is used to encode Template messages.
The value of index can range between 1 and 2,147,483,647. Index must be unique within all fields in a Template. (Nested Templates can reuse indexes). Once a Template is defined, the index cannot be changed, because it identifies the field in the actual storage format. Index is a mandatory field, but it is optional for top level fields, and map/array "values" definitions.
Optional.
Implementation
core.int? index;