refactor: this is nicer as a set

nedbat · nedbat · commit 2f7e38407321 · 2021-11-24T06:45:10.000-05:00
diff --git a/coverage/config.py b/coverage/config.py
@@ -233,11 +233,11 @@ def __init__(self):
         # Options for plugins
         self.plugin_options = {}
 
-    MUST_BE_LIST = [
+    MUST_BE_LIST = {
         "debug", "concurrency", "plugins",
         "report_omit", "report_include",
         "run_omit", "run_include",
-    ]
+    }
 
     def from_args(self, **kwargs):
         """Read config values from `kwargs`."""
