title: Discord.js - ReferenceError: DiscordCollection is not defined
body: <p>I was coding a bot using Discord.js, following Codelyon's code, and I am stuck with this error:</p>
  <pre><code>ReferenceError: DiscordCollection is not defined at Object.&lt;anonymous&gt;
  </code></pre>
  <pre class="lang-js prettyprint-override"><code>const {Client, Intents, DiscordAPIError, Collection} = require('discord.js');
  
  const client = new Discord.Client({ intents: [&quot;GUILDS&quot;, &quot;GUILD_MESSAGES&quot;] });
  
  const prefix = '-';
  
  const fs = require('fs');
  
  client.commands = new DiscordCollection();
  
  const commandFiles = fs.readdirSync(`./commands/`).filter(file =&gt; file.endsWith(`.js`));
  for(const file of commandFiles){
      const command = require(`./commands/${file}`);
  
      client.commands.set(command.name,command);
  }
  
  client.once('ready', () =&gt; {
      console.log('Ceeby Is Online');
  })
  
  client.on('message', message =&gt; {
      if(!message.content.startsWith(prefix) || message.author.bot) return;
  
      const args = message.content.slice(prefix.length).split(/ +/);
      const command = args.shift().toLowerCase();
  
      if(command === 'ping'){
          client.commands.get('ping').execute(message, args);
      }
  })
  client.login('TOKEN')
  </code></pre>