title: How to determine if a Key already exists in a NSMutableDictionary ignoring case
body: <p>I need to determine if the key of a new key value pair is unique before adding it to a NSMutableDictionary. How can I do this with case insensitivity? For example a new key called "my key" should not be validated if "My Key","MY KEY", or "my key",  etc. exists in the dictionary.</p>
  
  <p>I have tried ([myDictionary objectForKey:@"my key"] == nil) as well as ([[myDictionary allKeys] containsObject:@"my key"]) both of which are case sensitive.</p>
  
  <p>Thanks,</p>
  
  <p>John</p>