ARIA in HTML - test cases for select[aria-multiselectable]

Test 1

Authors SHOULD NOT use the aria-multiselectable attribute on a select element.

Expected result:
warning or error that aria-multiselectable is invalid on a native select element

Test 2

Authors SHOULD NOT use the aria-multiselectable attribute on a select element.

Expected result:
warning or error that aria-multiselectable is invalid on a native select element

Test 3

Authors SHOULD NOT use the aria-multiselectable attribute on a select element.

Expected result:
warning or error that aria-multiselectable is invalid on a native select element