---input---
go_gc_duration_seconds{instance="localhost:9090"} # single comment

---tokens---
'go_gc_duration_seconds' Name.Variable
'{'           Punctuation
'instance'    Name.Label
'='           Operator
'"'           Punctuation
'localhost:9090' Literal.String
'"'           Punctuation
'}'           Punctuation
' '           Text.Whitespace
'# single comment' Comment.Single
'\n'          Text.Whitespace