title: Method Illuminate\Support\Collection::exists does not exist
body: <p>I am trying to send mail to user. I don't know why its shows error.</p>
  
  <pre><code>$unUsedModuleIds=!$modulesIds-&gt;whereIn('id',$usedModuleIds)-&gt;exists();
  </code></pre>
  
  <p>when add this statement it's showing error. </p>
  
  <pre><code>foreach ($ModuleAutoMail as $module) {
      if ($mail-&gt;condition_id == '3') {
  
          $last_used_module = Carbon::parse($module-&gt;last_used_module);
          $DeferenceInDays = Carbon::parse(Carbon::now())-&gt;diffInDays($last_used_module);
  
          $usedModuleIds = module_auto_mail::where('user_id', $user_id)-&gt;pluck('module_id');
          $unUsedModuleIds = !$modulesIds-&gt;whereIn('id', $usedModuleIds)-&gt;exists();
  
  
          if ($unUsedModuleIds) {
              $ableToSendMail = true;
          }
  
          if ($DeferenceInDays &gt; 7) {
              $ableToSendMail = false;
          }
  
      }
  }
  </code></pre>