Add handling of block in response delegation (#3170)

Author: alextwoods

gems/aws-sdk-core/CHANGELOG.md

@@ -1,6 +1,8 @@
 Unreleased Changes
 ------------------
 
+* Issue - Add handling of block in response delegation (#3169). 
+
 3.216.0 (2025-01-15)
 ------------------
 

gems/aws-sdk-core/lib/seahorse/client/response.rb

@@ -75,6 +75,8 @@ def on_complete(&block)
       # Necessary to define as a subclass of Delegator
       # @api private
       def __getobj__
+        return yield if block_given? && !defined?(@data)
+
         @data
       end