diff --git a/swagger_parser/swagger_parser.py b/swagger_parser/swagger_parser.py
index <HASH>..<HASH> 100755
--- a/swagger_parser/swagger_parser.py
+++ b/swagger_parser/swagger_parser.py
@@ -27,7 +27,8 @@ class SwaggerParser(object):
         paths: dict of path with their actions, parameters, and responses.
     """
 
-    _HTTP_VERBS = {'get', 'put', 'post', 'delete', 'options', 'head', 'patch'}
+    _HTTP_VERBS = set('get', 'put', 'post', 'delete', 'options', 'head',
+                      'patch')
 
     def __init__(self, swagger_path=None, swagger_dict=None, use_example=True):
         """Run parsing from either a file or a dict.
fixed syntax issue breaking Python <I>

The `{foo, bar}` syntax for set literals was introduced in Python <I>. This should make the code work again for Python <I>.