title: Looping Through NSAttributedString Attributes to Increase Font SIze
body: <p>All I need is to loop through all attributes of <code>NSAttributedString</code> and increase their font size. So far I got to the point where I successfully loop through and manipulate attributes but I cannot save back to <code>NSAttributedString</code>. The line I commented out is not working for me. How to save back?</p>
  
  <pre><code>NSAttributedString *attrString = self.richTextEditor.attributedText;
  
  [attrString enumerateAttributesInRange: NSMakeRange(0, attrString.string.length)
                                 options:NSAttributedStringEnumerationReverse usingBlock:
   ^(NSDictionary *attributes, NSRange range, BOOL *stop) {
  
       NSMutableDictionary *mutableAttributes = [NSMutableDictionary dictionaryWithDictionary:attributes];        
  
       UIFont *font = [mutableAttributes objectForKey:NSFontAttributeName];
       UIFont *newFont = [UIFont fontWithName:font.fontName size:font.pointSize*2];         
       [mutableAttributes setObject:newFont forKey:NSFontAttributeName];
       //Error: [self.richTextEditor.attributedText setAttributes:mutableAttributes range:range];
       //no interfacce for setAttributes:range:
  
   }];
  </code></pre>