Getting NullPointerException while creating FTS index on newly couchbase docker image

I am getting Null pointer exception in following class:

AsyncSearchIndexManager.java:171

-> getAllIndexes()

-> return new ArrayList<>(indexes.values());

Here indexes is null and because of that I am getting error.

Reproduce step:

1. Start fresh Couchbase docker image,
2. try to create FTS index from java code, it fails due to NullPointerException.

Workaround:

1. Create any FTS index from Couchbase UI

2. Remove created FTS index ( remove if u want, that does not matter )

3. Run java code to execute FTS index, it works.

It works only if we create at-least one manually.

The reason is because 

"/api/index" is returning response { "status" : "ok", "indexDefs" : null } when we try to create index on fresh docker image because here indexDefs is null, it causing NullPointerException.

And after we create & delete any FTS index manually and after  that we are getting different response  { "status" : "ok", "indexDefs" : { "uuid" :"XXXX", "indexDefs": {}, "implVersion" :"5.6.0" } }