Remove unnecessary parentheses

lib/source_code.py

@@ -20,7 +20,7 @@ def get_source_code(func, strip_comments=False):
     if strip_comments:
         # TODO: less fragile way to do this (tokenizer sadly inserts whitespaces all around)
         comment_pattern = re.compile('^(\s.*)#.*$')
-        source = ''.join((
+        source = ''.join(
             line for line in StringIO(source).readlines() if re.match(comment_pattern, line) is None
-        ))
+        )
     return source