'@john-doe'   Name.Entity
' '           Text
'mentioned'   Text
' '           Text
'this'        Text
' '           Text
'issue'       Text
'\n'          Text.Whitespace

'\n'          Text.Whitespace

'@regular'    Name.Entity
' '           Text
'works'       Text
' '           Text
'too'         Text
'\n'          Text.Whitespace

'\n'          Text.Whitespace

'This'        Text
' '           Text
'is'          Text
' '           Text
'about'       Text
' '           Text
'#topic-name' Name.Entity
' '           Text
'and'         Text
' '           Text
'should'      Text
' '           Text
'highlight'   Text
'\n'          Text.Whitespace
