title: MongoDB $pull from array with filter
body: <p>I have User collection:</p>
  
  <pre><code>[
    {
      _id: '5b3935c2d4850aa2d9f0ae25',
      feedBucket: [
        {
          _id: '2a3535c2d4852ba2d9f0ae52',
          createdAt: '2018-06-30 21:52:22.681'
        },
        {
          _id: '9f342c2d4852ba2d9f0ae52',
          createdAt: '2018-06-30 21:52:22.681'
        }
      ]
    },
    {
      _id: '3d2343c2d4850aa2d9f0ae33',
      feedBucket: [
        {
          _id: '2a3535c2d4852ba2d9f0ae52',
          createdAt: '2018-02-30 21:52:22.681'
        },
        {
          _id: '9f342c2d4852ba2d9f0ae52',
          createdAt: '2018-06-30 21:52:22.681'
        }
      ]
    }
  ]
  </code></pre>
  
  <p>And I am trying to pull document with id - '9f342c2d4852ba2d9f0ae52' from users feedBucket.</p>
  
  <pre><code>await User.updateMany(
    {},
    { $pull: { feedBucket: { _id: '9f342c2d4852ba2d9f0ae52' } } },
    { multi: true }
  )
  </code></pre>
  
  <p>but it doesn't work, result is { n: 2, nModified: 0, ok: 1 }</p>