title: How to create an immutable NSAttributedString with a ranged attribute
body: <p>How can I initialize an <code>NSAttributedString</code> with a ranged attribute?</p>
  
  <p>As it stands, I can only work out how to add a ranged attribute after initialization, which obviously doesn't work for immutable <code>NSAttributedString</code> instances.</p>
  
  <p>If I have an <code>NSMutableAttributedString</code>, I can call:</p>
  
  <pre><code>[str addAttribute:NSLinkAttributeName value:url range:range];
  </code></pre>
  
  <p>If I have an <code>NSAttributedString</code>, I can construct it:</p>
  
  <pre><code>[[NSAttributedString alloc] initWithString:str attributes:@{NSLinkAttributeName: url}];
  </code></pre>
  
  <p>But I can't find a way to put a range into the attributesDict.</p>
  
  <p>Thanks,</p>