@startuml
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' Define the objects in the diagram
class "application bus" as AB
class "project bus" as PB
class "connection1" as C1

class "connection2" as C2
class "connection3" as C3
class "topic1-handler1" as T1H1

class "topic1-handler2" as T1H2
class "topic1-handler3" as T1H3

' Define the class relationships
AB o-- PB
AB *-- C1

PB *-- C2
PB *-- C3
C1 *-- T1H1

C2 *-- T1H2
C3 *-- T1H3
@enduml