title: A const list in C#
body: <p>I would like to create a list in C# that after its creation I won't be able to add or remove items from it. For example, I will create the list;</p>
  
  <pre><code>List&lt;int&gt; lst = a;
  </code></pre>
  
  <p>(a is an existing list), but after I won't be able to write the code (it will mark it as an error):</p>
  
  <pre><code>lst.Add(2);
  </code></pre>