file.js(2,16): error TS1097: 'extends' list cannot be empty.
file.js(5,16): error TS1097: 'extends' list cannot be empty.


==== file.js (2 errors) ====
    /** @augments X */
    class C extends {}
                   
!!! error TS1097: 'extends' list cannot be empty.
    
    /** @extends X */
    class D extends {}
                   
!!! error TS1097: 'extends' list cannot be empty.
    