✅ How to serialize IEnumerable<T> to json?

public IReadOnlyList<MessageQueueConsumeResultHeader>? Headers { get; init; }

public abstract class MessageQueueConsumeResultHeader
  {
    public abstract string Key { get; }

    public abstract byte[] GetValueBytes();

    public override string ToString()
    {
      return this.Key + " (" + string.Join<byte>(",", (IEnumerable<byte>) this.GetValueBytes()) + ")";
    }
  }