title: Error: string[] does not contain a definition for 'Contains' - works and doesn't work
body: <p>Working on an MVC5 app. I'm a little confused by this one.... I have 2 variables, both defined as string arrays (msUsers and msSites). One, msUsers, allows me to use "Contains", the other doesn't. Here's a snippet of the code....</p>
  
  <pre><code>    private IQueryable&lt;Event&gt; GetEventsFiltered(
          string userName,
          string workStatus,
          string[] msUsers,
          string[] msSites,
          int? eventTypeId)
      {
          IQueryable&lt;Event&gt; events = this.db.Events;
  
          if (msUsers != null)
          {
              events = events.Include(a =&gt; a.AspNetUser)
                  .Where(a =&gt; msUsers.Contains(a.AspNetUser.Id));
          }
  
          if (msSites != null)
          {
              // It doesn't like Contains here....
              events = events.Include(a =&gt; a.Branch)
                  .Where(a =&gt; msSites.Contains(a.Branch.Id));
          }
  </code></pre>
  
  <p>The error (for the last "Contains")...</p>
  
  <pre><code> 'string[]' does not contain a definition for 'Contains' and the best extension method 
    overload 'Queryable.Contains&lt;int&gt;(IQueryable&lt;int&gt;, int)' requires a receiver of type 
    'IQueryable&lt;int&gt;'
  </code></pre>
  
  <p>I'm a little confused because the first usage of Contains works fine against the SAME type of variable. Any suggestions/ideas? Thanks!</p>
  
  <p>***** UPDATED to add NAMESPACES ******</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Data.Entity;
  using System.Linq;
  using System.Net;
  using System.Web.Mvc;
  using System.Web.Security;
  
  using AuditingApp.Models;
  using AuditingApp.Services;
  using AuditingApp.ViewModels;
  
  using Microsoft.AspNet.Identity;
  </code></pre>