case: <!--
node: [Comment]
warn: []

case: <!---->
node: [Comment]
warn: []

case: <!---->beta
node: [Comment, Text(beta)]
warn: []

case: <!--->beta
node: [Comment]
warn: []

case: <!--<!--alpha-->-->beta
node: [Comment, Text(-->beta)]
warn: []

case: <!--alpha-->
node: [Comment]
warn: []

case: <!--alpha--> beta
node: [Comment, Text( beta)]
warn: []

case: <!--alpha--><!--beta
node: [Comment, Comment]
warn: []

case: <!--alpha--><!--beta-->
node: [Comment, Comment]
warn: []

case: <!--alpha-->beta
node: [Comment, Text(beta)]
warn: []

case: <!-<!--alpha-->beta
node: [Text(<!-), Comment, Text(beta)]
warn: [Warning(UnrecognizedTagName)]

case: alpha <!--beta
node: [Text(alpha ), Comment]
warn: []

case: alpha<!--beta
node: [Text(alpha), Comment]
warn: []