| name | Unique name of the search index. | 
| options | Indexing option set. | 
| roots | Search index roots, for example "Assets" to index all Assets under Assets. | 
| includes | Exclusive list of assets to be indexed. If this list is empty, everything will be indexed. | 
| excludes | Patterns to exclude assets to be indexed under roots. | 
| onIndexReady | Callback that gets invoked when the index is created and ready to be used. | 
Create a new search index.