@startuml
package com.iluwatar.bloc {

    class State {
        - value : int
        + State(value : int)
        + getValue() : int
    }

    interface StateListener<T> {
        + onStateChange(state : T)
    }

    interface ListenerManager<T> {
        + addListener(listener : StateListener<T>)
        + removeListener(listener : StateListener<T>)
        + getListeners() : List<StateListener<T>>
    }

    class BloC {
        - currentState : State
        - listeners : List<StateListener<State>>
        + BloC()
        + addListener(listener : StateListener<State>)
        + removeListener(listener : StateListener<State>)
        + getListeners() : List<StateListener<State>>
        - emitState(newState : State)
        + increment()
        + decrement()
    }

    class Main {
        + main(args : String[])
    }

    ListenerManager <|.. BloC
    StateListener <|.. BloC
    BloC o-- State
    BloC *--  StateListener
}
@enduml