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Apart from adding some extra information that gets thrown when the validation in listenerListToEndPoints  fails there are no changes outside of this specific case case.

Examples of listener configurations which will pass the validation proposed in this KIP

"PLAINTEXT://127.0.0.1:9092,PLAINTEXT://[::1]:9092"
"PLAINTEXT://[::1]:9093,PLAINTEXT://127.0.0.1:9093"
"PLAINTEXT://127.0.0.1:9094,PLAINTEXT://[::1]:9094,PLAINTEXT://127.0.0.1:9095,PLAINTEXT://[::1]:9095"
"PLAINTEXT://[::1]:9096,PLAINTEXT://127.0.0.1:9096,PLAINTEXT://[::1]:9097,PLAINTEXT://127.0.0.1:9097"

And here are examples of listener configurations which will fail the validation

"PLAINTEXT://[::1]:9092,PLAINTEXT://[::1]:9092"
"PLAINTEXT://127.0.0.1:9092,PLAINTEXT://127.0.0.1:9092"
"PLAINTEXT://127.0.0.1:9092,PLAINTEXT://127.0.0.1:9092,PLAINTEXT://127.0.0.1:9092"
"PLAINTEXT://127.0.0.1:9092,SSL://127.0.0.1:9092,SASL_PLAINTEXT://127.0.0.1:9092"

Compatibility, Deprecation, and Migration Plan

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