queryCommandSupported("selectall"): true
queryCommandEnabled("selectall"): true
execCommand("selectall"): PASS
queryCommandSupported("SELECTALL"): true
queryCommandEnabled("SELECTALL"): true
execCommand("SELECTALL"): PASS
queryCommandSupported("SeLeCtAlL"): true
queryCommandEnabled("SeLeCtAlL"): true
execCommand("SeLeCtAlL"): PASS