In some cases it's possible that a list may be used as the key of a dictionary, which would raise an exception because python lists are not hashable. Therefore, when this happens, we need to convert the list to tuple, which can be hashed.
Coverage: 99.635% (+0.0004%) from 99.635% when pulling 351a5ae5645326a479a16bf6841b834f5ad95864 on fix-unashable-type-list into 859b0ebc4ab11dbfebb983126dbf9a9cbc346da6 on master.
In some cases it's possible that a list may be used as the key of a dictionary, which would raise an exception because python lists are not hashable. Therefore, when this happens, we need to convert the list to tuple, which can be hashed.