14:06:20.873 TestPlan Error running "Test Step Example": Value cannot be null.
Parameter name: key.
14:06:20.873 TestPlan ArgumentNullException: Value cannot be null.
Parameter name: key
14:06:20.874 TestPlan at System.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)
14:06:20.874 TestPlan at System.Collections.Generic.Dictionary`2.FindEntry(TKey key)
14:06:20.874 TestPlan at Python.Runtime.MethodBinder.MatchesArgumentCount(Int32 positionalArgumentCount, ParameterInfo[] parameters, Dictionary`2 kwargDict, Boolean& paramsArray, ArrayList& defaultArgList, Int32& kwargsMatched, Int32& defaultsNeeded)
14:06:20.874 TestPlan at Python.Runtime.MethodBinder.Bind(BorrowedReference inst, BorrowedReference args, Dictionary`2 kwargDict, MethodBase[] methods, Boolean matchGenerics)
14:06:20.874 TestPlan at Python.Runtime.MethodBinder.Bind(BorrowedReference inst, BorrowedReference args, BorrowedReference kw, MethodBase info, MethodBase[] methodinfo)
14:06:20.874 TestPlan at Python.Runtime.MethodBinder.Invoke(BorrowedReference inst, BorrowedReference args, BorrowedReference kw, MethodBase info, MethodBase[] methodinfo)
14:06:20.874 TestPlan at Python.Runtime.MethodObject.Invoke(BorrowedReference target, BorrowedReference args, BorrowedReference kw, MethodBase info)