title: What does an asterisk in front of a constant mean?
body: <p>I see this <code>*MyModel::MY_CONSTANT</code></p>
  
  <p>and it references this in MyModel:</p>
  
  <pre><code>  MY_CONSTANT = [
      :a_field,
      :another_field,
    [
  </code></pre>
  
  <p>When called as</p>
  
  <pre><code>permit(:name, *MyModel::MY_CONSTANT)
  </code></pre>
  
  <p>it expands to</p>
  
  <pre><code>permit(:name, :a_field, :b_field)
  </code></pre>
  
  <p>but what just happened?</p>