known role="foo button" data-testname="unknown[role=button] ignoring invalid foo role token" aria-label="x" data-expectedrole="button" class="ex">x</unknown>

  <!-- known el and invalid role(s) -->
  <button role="foo" data-testname="button ignoring single invalid role token" aria-label="x" data-expectedrole="button" class="ex">x</unknown>
  <button role="foo bar" data-testname="button ignoring multiple invalid role tokens" aria-label="x" data-expectedrole="button" class="ex">x</unknown>

  <!-- known el w