solargraph: autocompletion does not work if array given for an object

When I declare type for solargraph and fetch an object from an array, autocompletion does not work. See here:

If I do this by giving a method or a static member then it works:

Basically, anything[] type does not support autocomplete. I cannot see methods in it.

Sample:

    # @type [Reserve]
    source = Reserve[source_id]
    # @type [Reserve]
    another = anonymous_method()
    
    source. # does not work.
    another. # works.