Objective-c method to use blocks
<p>I have a method that calls a long running process. the long running process and I use AFNetworking which itself uses blocks and returns success block and failure block.  So I am trying to test my method and the tests will fail before the success block is called.  I thought I would try to get my method to also use blocks.  I have another method that I managed to change to use blocks but that only uses bool isFinished and the return value is void.  The method I have difficult with needs to return NSDecimalNumber* and takes an NSString.</p>

<p>Method signature</p>

<ul>
<li>(NSDecimalNumber*) getRate:(NSString*) rateCode;  </li>
</ul>

<p>I would like to be able to able to add a completion block with a BOOL that I set when the AFNetworking method enters the success block</p>

<p>I would also like to be able to call the method and within it's completion block access the NSDecimalNumber* value it returned</p>

<p>Possible?  If so please show me how</p>