title: How to assert all items in a collection using fluent-assertions?
body: <p>Say I want to test a method returning a bunch of items of the following type using <a href="https://github.com/dennisdoomen/fluentassertions/">fluent-assertions</a> to ensure that all items have their <code>IsActive</code>-flag set to <code>true</code>:</p>
  
  <pre><code>public class Item
  {
      public bool IsActive { get; set; }
  }
  </code></pre>
  
  <p>To achieve that I could simply iterate over the collection and assert every item separately in a foreach-loop:</p>
  
  <pre><code>var items = CreateABunchOfActiveItems();
  foreach (var item in items)
  {
      item.IsActive.Should().BeTrue("because I said so!");
  }
  </code></pre>
  
  <p>But is there a more fluent way to assert every item in the whole collection at once?</p>