@startuml
abstract class AbstractConfig {
    #$storage
    +__construct($storage)
}

class ArrayConfig {
    +get($key : string|int, $default = null)
    +set($key : string|int, $value : mixed)
}

class Connection {
    #$configuration : Parameters
    #$host
    +__construct(Parameters $config)
    +connect()
    +getHost()
}

interface Parameters {
    +get($key : string|int)
    +set($key, $value : mixed)
}

AbstractConfig <|.. ArrayConfig
Parameters <|.. ArrayConfig

@enduml