Previously calling `index.New` would return an object with the index information such as the Indexer, whether it was required, and the name of the index as well as a radix tree to store indexed data.
Now the main `Index` type doesn’t contain the radix tree for indexed data. Instead the `IndexedData` method can be used to combine the main `Index` with a radix tree in the `IndexedData` structure.
The cache still only allows configuring the `Index` type and will invoke the `IndexedData` method on the provided indexes to get the structure that the cache can use for actual data management.
All of this makes it now safe to reuse the `index.Index` types.
Matt Keeler