SpringBoot org.springframework.boot.SpringApplication#callRunners

Hello，I am a newbie There is a place that I don't understand org.springframework.boot.SpringApplication#callRunners There are in the method body new LinkedHashSet Why create a new object? Don't understand. Help me answer and get out of the confusion, thanks.

Comment From: philwebb

Creating a new LinkedHashSet is used to ensure any duplicates in the ArrayList are removed. It's possible that a bean is both an ApplicationRunner and a CommandLineRunner, in which case we don't want to call it twice.

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