FIX: toSequence fails for `None`

saqc/lib/tools.py

@@ -43,6 +43,8 @@ def assertScalar(name, value, optional=False):
 
 
 def toSequence(value: T | Sequence[T]) -> List[T]:
+    if value is None:  # special case
+        return [None]
     if isinstance(value, T.__constraints__):
         return [value]
     return list(value)