public boolean hasStreaming() {
        return (searchCluster != null) && searchCluster.hasStreaming();
    }
Returns whether the schemas in this cluster use streaming mode.

@return True if this cluster only has schemas with streaming mode, False if it only has schemas
        with indexing, null if it has both or none.
config-model/src/main/java/com/yahoo/vespa/model/content/ContentSearchCluster.java