
FAIL CustomStateSet behavior of ElementInternals.states: Initial state this.attachInternals is not a function. (In 'this.attachInternals()', 'this.attachInternals' is undefined)
FAIL CustomStateSet behavior of ElementInternals.states: Exceptions this.attachInternals is not a function. (In 'this.attachInternals()', 'this.attachInternals' is undefined)
FAIL CustomStateSet behavior of ElementInternals.states: Modifications this.attachInternals is not a function. (In 'this.attachInternals()', 'this.attachInternals' is undefined)
FAIL Updating a CustomStateSet while iterating it should work this.attachInternals is not a function. (In 'this.attachInternals()', 'this.attachInternals' is undefined)