Returns a Boolean value that indicates whether the receiver contains a given object.
The object to search for in the receiver.
YES if the receiver contains object, otherwise NO.
Currently, doesContain: messages are never sent to any object from within Cocoa itself.
The default implementation for this method provided by NSObject returns YES if the receiver is actually an NSArray object and an indexOfObjectIdenticalTo: message sent to the same object would return something other than NSNotFound.