address review comments
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 9fa7cca..23abda3 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -763,7 +763,7 @@
       tests_by_assembly = json.load(f)
 
     msbuild_config = _MSBUILD_CONFIG[self.config.build_config]
-    nunit_args = ['--labels=All','--noresult', '--workers=1']
+    nunit_args = ['--labels=All', '--noresult', '--workers=1']
     assembly_subdir = 'bin/%s' % msbuild_config
     assembly_extension = '.exe'