@startuml
<style>
  title {
    BackGroundColor transparent
    FontColor black
    HorizontalAlignment center
  }  
</style>
label l [
{{
!theme reddress-lightorange
title reddress-lightorange
Alice -> Bob: reddress-lightorange
Bob -> Alice: reddress-lightorange
}}
{{
title ___________________________________  
}}
{{
!theme reddress-lightred
title reddress-lightred
Alice -> Bob: reddress-lightred
Bob -> Alice: reddress-lightred
}}
{{
title ___________________________________  
}}
{{
!theme sandstone
title sandstone
Alice -> Bob: sandstone
Bob -> Alice: sandstone
}}
{{
title ___________________________________  
}}
{{
!theme silver
title silver
Alice -> Bob: silver
Bob -> Alice: silver
}}
{{
title ___________________________________  
}}
{{
!theme sketchy-outline
title sketchy-outline
Alice -> Bob: sketchy-outline
Bob -> Alice: sketchy-outline
}}
{{
title ___________________________________  
}}
{{
!theme sketchy
title sketchy
Alice -> Bob: sketchy
Bob -> Alice: sketchy
}}
{{
title ___________________________________  
}}
{{
!theme spacelab-white
title spacelab-white
Alice -> Bob: spacelab-white
Bob -> Alice: spacelab-white
}}
{{
title ___________________________________  
}}
{{
!theme spacelab
title spacelab
Alice -> Bob: spacelab
Bob -> Alice: spacelab
}}
{{
title ___________________________________  
}}
{{
!theme superhero-outline
title superhero-outline
Alice -> Bob: superhero-outline
Bob -> Alice: superhero-outline
}}
{{
title ___________________________________  
}}
{{
!theme superhero
title superhero
Alice -> Bob: superhero
Bob -> Alice: superhero
}}
{{
title ___________________________________  
}}
{{
!theme toy
title toy
Alice -> Bob: toy
Bob -> Alice: toy
}}
{{
title ___________________________________  
}}
{{
!theme united
title united
Alice -> Bob: united
Bob -> Alice: united
}}
{{
title ___________________________________  
}}
{{
!theme vibrant
title vibrant
Alice -> Bob: vibrant
Bob -> Alice: vibrant
}}
{{
title ___________________________________  
}}
]
@enduml