fullTextIndex
Create a full-text index expression referencing a full-text index with the given index name.
When there is a need to specify the data source in which the index has been created (e.g. in multi-collection join statement, calls the from(_ alias: String) method from the returned FullTextIndexExpressionProtocol object to specify the data source.
Return
The full-text index expression referring to a full text index in the specified data source.
Parameters
indexName
The name of the full-text index.