tests: imap test for exception handler returns value

tests.py

@@ -202,6 +202,18 @@ def exception_handler(request, exception):
             out.append(r)
         self.assertEquals(out, [])
 
+    def test_imap_timeout_exception_handler_returns_value(self):
+        """
+        ensure behaviour for a handler that returns a value
+        """
+        def exception_handler(request, exception):
+            return request
+        reqs = [grequests.get(httpbin('delay/1'), timeout=0.001)]
+        out = []
+        for r in grequests.imap(reqs, exception_handler=exception_handler):
+            out.append(r)
+        self.assertEquals(out, [])
+
     def test_map_timeout_exception(self):
         class ExceptionHandler:
             def __init__(self):