class constructor in c#

public class Ping : ICommand {
    private readonly DiscordClient discord;
    private readonly SocketUserMessage message;

    public Ping(DiscordClient discord, SocketUserMessage message) {
        this.discord = discord;
        this.message = message;
    }
}

public class Ping(DiscordClient discord, SocketUserMessage message) : ICommand {
    private readonly DiscordClient discord = discord;
    private readonly SocketUserMessage message = message;
}